YOU ARE WHAT YOU EAT         i
TABLE OF CONTENTSCHAPTER ONE    1.0 Introduction                                   1    1.1 Nutrition                     ...
CHAPTER ONE1.0 INTRODUCTIONThe phrase “You are what you eat” gives the notion that to be fit and healthy mentallyand physi...
way of food and drink (except oxygen); the material gained during intrauterine growthcame from the mother’s diet. Therefor...
availability, economy, cultural and social habits, physiological and psychologicalattributes, marketing methods, and nutri...
Physiological functions of foodi. Energy yielding foods: Foods rich in carbohydrates and fats are called energy yieldingfo...
1.3 NUTRIENTS AND THEIR FUNCTIONSAny chemical substance that can be used by an organism to sustain its metabolicactivities...
Functions of CarbohydratesCarbohydrates perform the following functions.1. Energy: The principle function of carbohydrates...
Food Sources of CarbohydratesCereal grains, roots and tubers are the major sources of starch. Fruits and vegetablescontain...
Starch     salivary, pancreatic      maltose + Isomaltose           & intestinal amylaseGlycogen is also broken by these e...
At least 40 percent of the total energy in the food should come from Carbohydrates. Inour country 60 – 80 percent of a day...
One fifth of an adults total body weight is protein. Protein is found in every cell of ourbody. All the tissues in our bod...
proteins. A complete protein contains all essential amino acids in relatively the sameamounts as human beings require to p...
6. Acid-base balance: Proteins help maintain the acid-base balance of the body fluids byacting as buffers.7. Energy: Prote...
absorbed by the mechanism of pinocytosis. Absorbed amino acids pass into the portalblood and reach liver where they are co...
1.3.3 LIPIDSLipids more commonly known as fats and oil are integral part of our food. They areinsoluble in water but solub...
Essential and Non – Essential fatty acidEssential fatty acid (EFA) are those which cannot be synthesized by the body and n...
3) Acts as precursor of hormone like – prostaglandin which aid in regulating vascularfunction and help relieving pain and ...
a) Plant sources: All common vegetable oils with the exception of coconut oils arepredominantly unsaturated. The invisible...
Digestion Absorption and UtilizationDigestionIn the mouth: Fat digestion starts in the mouth with hard fats beginning to m...
Majority of lipids enter via the lymph to the liver where the protein and lipid (cholesterol,triglycerides) are bound toge...
MINERALS AND VITAMINSUntil the middle of the nineteenth century, the importance of minerals and vitamins wasnot known. It ...
2. Tooth formation: - C and P together are essential for dentin and enamel formation.3. Physiological Process: -a. C is es...
Osteomalacia – is a condition in which the quality but not the quantity of bone isreduced. This condition results from def...
Food SourcesThe iron present in food can be as haem and non-haem iron depending upon the sourcefrom which it is obtained. ...
1.3.5 VITAMINSVitamins are organic substances present in small amounts in food, they are required forcarrying out vital fu...
the vitamin. Vitamin A in the diet comes in two forms. Retenoids (preformed Vitamin A)and carotenoids. Vitamin A is presen...
Vitamin A. In the absence of adequate Vitamin A intake the outer lining of the eye ballloses its usual moist, white appear...
Food SourcesThe Vitamin D content of food sources from animals varies with the diet, breed andexposure to sunlight of the ...
2. deformities of the limbs, spine, thorax and pelvis3. demineralization of the bones4. pain in pelvis, lower back and leg...
Effects of Deficiency: Prolonged deficiency of ascorbic acid produces a diseasecondition called as ‘scurvy’ in both infant...
RequirementsThiamine is involved in the carbohydrate metabolism. Its requirement is related to energyderived from carbohyd...
1.3.6 WATERWater makes up about 70% of the weight of human. For each 100kcal of energymetabolized, animals can manufacture...
Functions of Water1. It is an essential constituent of all the cells of the body and the internal environment.2. Serves as...
of nutrients are dependent on pH. Most body fluids are near neutral with the exception ofgastric juice. The pH value of so...
Daily Water InputIn tropical countries like Nigeria the daily water input amounts to 2400 – 3000 ml ofwater through food, ...
Oral rehydration therapyIt is the administration of fluid to prevent or correct dehydration.Oral rehydration saltWHO, UNIC...
CHAPTER TWO2.0 HEALTHY NUTRITIONHealth is defined by the World Health Organization (WHO) as the “State of completephysical...
years to life, especially a better quality of life in later life through the reduction of risk ofmany chronic conditions r...
o Children (25–60 months)• Give diet that contains a variety of foods in adequate amounts.• Add palm oil or vegetable oil ...
• Diet should consist of as wide a variety of foods as possible for example, cereals,   legumes, roots/tubers, fruits, veg...
• Children and adolescents should engage in leisure time exercise   • Adults should undertake some form of exercise as rec...
By incorporating the principle of balance, variety and moderation, an individual can stilleat their favorite foods while f...
• American Cancer Society And National Cancer Institute Guidelines   • World Health Organization Recommendations   • other...
the amount of calories in the foods and drinks they consume with the amount of caloriesthe body uses. Physical activity is...
Some dietary fat is needed for good health. Fats supply energy and essential fatty acidsand promote absorption of the fat-...
sources of polyunsaturated fats. Both kinds of unsaturated fats reduce blood cholesterolwhen they replace saturated fats i...
at risk for high blood pressure reduce their chances of developing this condition byconsuming less salt or sodium. Some qu...
disease via its mechanism of neutralizing free radicals and thwarting enzymes that   activate cancer causing agents in the...
CHAPTER THREE3.0 UNHEALTHY NUTRITIONEach passing day, due to faulty eating habit various hazardous agents enter our bodyth...
Poor nutrition can also impair neural development, leading to lower intelligence quotientin humans and flawed song learnin...
b) Over Nutritionc) Nutritional deficienciesd) Individuals at the risk of developing malnutritione) Individuals at the ris...
Bulimia NervosaCharacterized by recurrent episodes of eating unusually large quantities of food at a meal,and eating until...
do not present for treatment until they are much older and already overweight or obese(Christian, 2007).Implications   •  ...
Compared to immediate oxidation, the energy cost of converting glucose into glycogen is5%, and into fat is 28%.       Body...
In the CARDIA study, 4304 young adults were followed for over 15 years in amulticenter, population-based, prospective stud...
Alcoholic beverages have been consumed by humans since the dawn of history. Theyhave been used to ease anxiety, to promote...
You are what you eat final (APEH Daniel O.)
You are what you eat final (APEH Daniel O.)
You are what you eat final (APEH Daniel O.)
You are what you eat final (APEH Daniel O.)
You are what you eat final (APEH Daniel O.)
You are what you eat final (APEH Daniel O.)
You are what you eat final (APEH Daniel O.)
You are what you eat final (APEH Daniel O.)
You are what you eat final (APEH Daniel O.)
You are what you eat final (APEH Daniel O.)
Upcoming SlideShare
Loading in …5
×

You are what you eat final (APEH Daniel O.)

1,245 views
1,116 views

Published on

Published in: Health & Medicine, Technology
0 Comments
1 Like
Statistics
Notes
  • Be the first to comment

No Downloads
Views
Total views
1,245
On SlideShare
0
From Embeds
0
Number of Embeds
0
Actions
Shares
0
Downloads
18
Comments
0
Likes
1
Embeds 0
No embeds

No notes for slide

You are what you eat final (APEH Daniel O.)

  1. 1. YOU ARE WHAT YOU EAT i
  2. 2. TABLE OF CONTENTSCHAPTER ONE 1.0 Introduction 1 1.1 Nutrition 2 1.2 Food 2 1.2.1 Functions of Food 3 1.3 Nutrients and Their Functions 5 1.3.1 Carbohydrates 5 1.3.2 Protein 10 1.3.3 Lipids 14 1.3.4 Minerals 20 1.3.5 Vitamins ` 24 1.3.6 Water 31CHAPTER TWO 2.0 Healthy Nutrition 36 2.1 Dietary Guidelines 37 2.2 Food Pyramid 40 2.3 Eating Tips for a Healthy Nutrition 2.4 Effects of Healthy Nutrition 42CHAPTER THREE 3.0 Unhealthy Nutrition 46 3.1 Malnutrition 48 3.2 Eating Disorders 49 3.3 Selected Food Related Disease Conditions 3.3.1 Obesity 50 3.3.2 Hypertension 53 3.3.3 Hyperinsulinism 53 3.3.4 Alcoholism 54CHAPTER FOUR 4.0 Food and the Mind 57 4.1 How Food Interacts with your Brain 57 4.2 Food and Mental Health 58 4.3 Conclusion 62REFERENCES 63 ii
  3. 3. CHAPTER ONE1.0 INTRODUCTIONThe phrase “You are what you eat” gives the notion that to be fit and healthy mentallyand physiologically you need to eat good food. This phrase has come to us via quite atortuous route. Anthelme Brillat-Savarin wrote, in Physiologie du Gout, ou Meditationsde Gastronomie Transcendante, 1826: "Dis-moi ce que tu manges, je te dirai ce que tues." (Tell me what you eat and I will tell you what you are). The actual phrase didntemerge in English until sometime later. In the 1920s and 30s, the nutritionist VictorLindlahr, who was a strong believer in the idea that food controls health, developed the‘Catabolic Diet’. This view gained some adherents at the time and the earliest knownprinted example is from an advert for beef in a 1923 edition of the Bridgeport Telegraph,for United Meet Markets in which they said "Ninety per cent of the diseases known toman are caused by cheap foodstuffs. You are what you eat." In 1942, Lindlahr publishedYou Are What You Eat: how to win and keep health with diet. That seems to be thevehicle that took the phrase into the public consciousness.However, in the interlocution with the Jews in the gospel (John 6:51-58), our Lord JesusChrist established that he has a kind of food of which if we eat, we will not only nothunger for any other food. This food is actually his flesh and his blood, when we partakein them we become one with him because we are assimilated into him; establishing thefact that we become what we eat.The food you put into your body is what your body will use in the construction andreplacement of its cells, hormones and neurotransmitters. Quite literally then you arecomposed of the very food you consume. It is logical then to say a body constructed ofempty calorie food and low nutrition will be inferior to a body constructed fromwholesome food in the correct quantities (The leaf catcher, 2012).Nutrition, health and wellness are intricately related and therefore, aberration in ournutrition, by way of what we eat and do and also how we prepare what we eat, tend toinfluence significantly on our health and well-being i.e. how we feel and how long welive. Virtually all material in the body mass which has been gained entered the body by 1
  4. 4. way of food and drink (except oxygen); the material gained during intrauterine growthcame from the mother’s diet. Therefore, we are literally what we eat, but genetic factorsinfluence how this nutritional input is used (Garrow et al., 2000).1.1 NUTRITIONNutrition as defined by Robinson (1982) is “ the science of foods and nutrients, theiraction, interaction and balance in relationship to health and disease, the processes bywhich the organism ingests, digests, absorbs, transports and utilizes nutrients anddisposes of their end product”. Nutrients are the constituents in food that must besupplied to the body in adequate amounts. These include Carbohydrates, Proteins, Fats,Minerals and Vitamins; Water is included in current lists. Nutritional status is thecondition of health of the individual as influenced by the utilization of the nutrients.The science of Nutrition has been developed by using the combined knowledge of thephysical and biological sciences. Its application involves the social sciences related toman’s behavior – Psychology, sociology, anthropology and economics. Until World WarI the significance of nutrition was recognized by a relatively small group of scientists andphysicians. Since then, a wider awareness has developed on the role of nutrients in healthof individuals and the economic development of the nation (Carolyn et al., 2007).A great number of important discoveries and developments in this field have enabledhealth care professionals to understand the nutrient needs of people and the means ofsupplying them.1.2 FOODFood refers to any material that can be ingested by an organism and metabolized toprovide energy and precursors for biosynthetic reactions. Humans and animals consumefood to obtain the nutrients they need. Throughout the world there are differences in foodconsumption related to socioeconomic conditions, food availability, and cultural dictates(Carolyn et al., 2004). Food is used to satisfy hunger, provide comfort and relief fromboredom or anxiety, as a status symbol, as well as in the performance of various ritualsand rites. Several factors influence the choice of the food we eat. These include 2
  5. 5. availability, economy, cultural and social habits, physiological and psychologicalattributes, marketing methods, and nutritional knowledge, among others (Clarke andHerbert, 1986). The food we eat should be safe, palatable, affordable, and of the qualitythat can maintain mental, emotional, physiologic and physical health. As a deviation fromthe above, food have been found to contain any or some of the following; • Nutrients • Microorganism –Pathogenic and non-pathogenic • Poisons in form of metal contaminants • Secondary metabolites of sources ranging from plant, animals, fungi e.t.c. • Antinutrients1.2.1 FUNCTIONS OF FOODFoods have physiological, social and psychological functions as shown by Sheil et al(2004). 3
  6. 6. Physiological functions of foodi. Energy yielding foods: Foods rich in carbohydrates and fats are called energy yieldingfoods. They provide energy to sustain the involuntary processes essential for continuanceof life, to carry out various professional, household and recreational activities and toconvert food ingested into usable nutrients in the body. The energy needed is supplied bythe oxidation of foods consumed. Cereals, roots and tubers, dried fruits, oils, butter andghee are all good sources of energy.ii. Body building foods: Foods rich in protein are called body building foods. Milk,meat, eggs and fish are rich in proteins of high quality. Pulses and nuts are good sourcesof protein but the protein is not of high quality. These foods help to maintain life andpromote growth. They also supply energy.iii. Protective and Regulatory foods: Foods rich in protein, minerals and vitamins areknown as protective and regulatory foods. They are essential for health and regulateactivities such as maintenance of body temperature, muscle contraction, control of waterbalance, clotting of blood, removal of waste products from the body and maintainingheartbeat. Milk, egg, liver, fruits and vegetables are protective foods.Social functions of foodFood has always been the central part of our community, social, cultural and religiouslife. It has been an expression of love, friendship and happiness at religious, social andfamily get-togethers.Psychological functions of foodIn addition to satisfying physical and social needs, foods also satisfy certain emotionalneeds of human beings. These include a sense of security, love and acceptance. Forexample, preparation of delicious foods for family members is a token of love andaffection. 4
  7. 7. 1.3 NUTRIENTS AND THEIR FUNCTIONSAny chemical substance that can be used by an organism to sustain its metabolicactivities is a nutrient. There are six basic types of nutrient (Sheila et al., 2004).1.3.1 CARBOHYDRATESEnergy that is needed to move, perform work and live is chiefly consumed in the form ofcarbohydrates. Carbohydrates, primarily starches, are least expensive, easily obtained andreadily digested form of fuel. Carbohydrates are organic compounds composed of carbon,hydrogen and oxygen, with the later elements in the ratio of 2:1. The general formula isCnH2nOn. They are viewed as hydrated carbon atoms.Classification – simple and complex carbohydratesCarbohydrates are classified, depending on the number of sugar units they contain, assimple carbohydrate and complex carbohydrates.Monosaccharides and disaccharides make up simple carbohydrates, called simple sugarscontaining one and two sugar units respectively. Polysaccharides called complexcarbohydrates are structurally larger and more complex than simple sugars. They includestarch, dietary fibre and glycogen (Sheila et al., 2004). 5
  8. 8. Functions of CarbohydratesCarbohydrates perform the following functions.1. Energy: The principle function of carbohydrates is to serve as a major source ofenergy for the body. Each gram of carbohydrate yields 4Kcal of energy regardless of itssource. In Indian diets 60 – 80 % of energy is derived from carbohydrate.2. Glucose: Glucose is indispensable for the maintenance of the functional integrity ofthe nervous tissue and is the sole source of energy for the proper functioning of the brain.Prolonged lack of glucose may cause irreversible damage to the brain.3. Protein Sparing Action: Carbohydrates exert a protein sparing action. If sufficientamounts of carbohydrates are not available in the diet, the body will convert protein toglucose in order to supply energy. Hence to spare proteins for tissue building,carbohydrates must be supplied in optimum amounts in the diet. This is called the proteinsparing action of carbohydrates.4. Synthesis of Body Substances: Carbohydrates aid in the synthesis of nonessentialaminoacids, glycoproteins (which function as antibodies) and glycolipids (which form apart of cell membrane in body tissues especially brain and nervous system).5. Precursors of Nucleic Acid: Carbohydrates and products derived from them, serve asprecursors of compounds like nucleic acids, connective tissue matrix and galactosides ofnervous tissue.6. Detoxification Function: Glucuronic acid, a metabolite of glucose serves as adetoxifying agent. It combines with harmful substances containing alcohol or phenolicgroup converting them to harmless compounds which are later excreted.7. Roughage of the Diet: Insoluble fibres known as composite carbohydrates can absorbwater and give bulk to the intestinal contents which aids in the elimination of wasteproducts by stimulating peristaltic movements of the gastrointestinal tract. 6
  9. 9. Food Sources of CarbohydratesCereal grains, roots and tubers are the major sources of starch. Fruits and vegetablescontain varying amounts of monosaccharides and dissaccharides. Sugar is obtained fromsugarcane.Types and sources of Carbohydrates are given in the table belowS/No Carbohydrate Food Source1 Monosaccharides Glucose Fruits, honey, corn-syrup. Fructose Fruits, honey. Galactose, Maltose These do not occur in free form in foods.2 Dissaccharides Sucrose Cane and beet sugar. Lactose Milk and milk products. Maltose Malt and Cereal products3 Polysaccharides Digestible: Starch & Dextin Grains, vegetables especially roots& tubers and legumes Glycogen Meat products and seafoods Indigestible: Cellulose Stalks and leaves of vegetables, outer coat of Pectins, Gums seeds Fruits, Plant secretions and seeds.Digestion, Absorption and UtilizationDigestionThe first stage of digestion of carbohydrate takes place in the mouth. Chewing breaks upfood and exposes starch and sugars to the action of enzymes. Saliva contains salivaryamylase (ptyalin). It converts starch to maltose but time limits the action of salivaryamylase, because as food enters the stomach, the acid present in the stomach blocks theaction of salivary amylase.In the stomach the acid causes hydrolysis of sucrose. In the small intestine pancreaticamylase and intestinal amylase digest starch up to the stage of maltose. 7
  10. 10. Starch salivary, pancreatic maltose + Isomaltose & intestinal amylaseGlycogen is also broken by these enzymes to dissacharides. Enzymes maltase, sucraseand lactase present in the brush borders of the columnar cells of small intestine convertdissacharides to monosaccharides.Maltose Maltase Glucose + GlucoseLactose Lactase Glucose + GalactoseSucrose Sucrase Glucose + FructoseCellulose and other polysaccharides are not digested by enzymes, so undigested materialpasses to large intestine forming bulk which contributes to faeces. The end products ofcarbohydrate digestion are monosaccharides – glucose, galactose and fructose.MetabolismMetabolism occurs inside the various cells of the body. There are two types ofmetabolism; anabolism (building up) and catabolism (breaking down).The major carbohydrate anabolic pathways are conversion of glucose into glycogen(glycogenesis) in the liver and muscles. The conversion of glucose into fat (lipogenesis)in the liver and adipose tissue.Carbohydrates follow two major catabolic pathways:The breakdown of glucose releasing energy (glycolysis) and converting it into usableenergy (ATP) and the conversion of glycogen to glucose (glycogenolysis).After digestion and absorption of glucose into the blood stream it is utilized directly bythe tissues for energy, when the absorbed glucose exceeds the body’s need for energy it isstored as glycogen in the liver and muscle and excess glucose is converted totriglycerides and stored as fat in adipose tissue.Requirements 8
  11. 11. At least 40 percent of the total energy in the food should come from Carbohydrates. Inour country 60 – 80 percent of a day’s energy needs are met from carbohydrates in theform of starch furnished by majorly grains. In developed countries only 30 – 40 percentof days energy needs are met from carbohydrates.Dietary FibreDietary fibre is defined as that portion of plant material ingested in the diet that isresistant to digestion by gastrointestinal secretions. It consists of hemicellulose, cellulose,lignins, oligosaccharides, pectins, gums and waxes. Some bacteria in the large intestinecan degrade some components of fibre releasing products, that can be absorbed into thebody and used as energy source.Two categories of fibre are found in food. Crude fibre is defined as the residue remainingafter the treatment with hot sulphuric acid, alkali and alcohol.The major component of crude fibre is a polysaccharide called cellulose. Crude fibre is acomponent of dietary fibre. Several other carbohydrate and related compounds calledpectins, hemicellulose and lignins are the second category found in plant foods and arealso resistant to digestion.1.3.2 PROTEIN 9
  12. 12. One fifth of an adults total body weight is protein. Protein is found in every cell of ourbody. All the tissues in our body such as muscle, blood, bone, skin and hair are made upof proteins. Many hormones and enzymes are either protein or protein derivatives. Thenucleic acids in the cell nucleus occur in combination with proteins as nucleoproteins.Protein is thus essential to maintain cellular integrity and function and for health andreproduction.Protein is synthesized from basic units called amino acids. Protein molecules, whichcontain up to hundred amino acids are much larger than carbohydrates or lipid molecule.Chemically amino acids are composed of a carbon atom to which is attached a carboxyl(COOH) group, a hydrogen atom (H), an amino group (NH 2) and an amino acid radical(R) as shown below. They are distinguished from carbohydrates and fats by the presence of nitrogen. The carboxyl group, the amino group and COOH the hydrogen atom are the same for all amino acids. H C R The R group distinguishes one amino acid from NH2 another. Structure of an Amino acid. A protein is made upon of chains of amino acids joinedto each other by a peptide linkage. The amino group of one amino acid is linked to thecarboxyl group of another amino acid by removal of water. Proteins consist ofPolypeptides (Sheila et al., 2004).Nutritionally Essential and Non-Essential Amino AcidsAn essential amino acid is one that cannot be synthesized by the body and hence shouldbe supplied by the diet. The essential amino acids are histidine, isoleucine, leucine,lysine, methionine, phenylalanine, threonine, tryptophan and valine. Non-essential aminoacids are those that the body can synthesize. They are alanine, arginine, aspargine,aspartic acid, cysteine, glutamic acid, glutamine, glycine, proline, serine and tyrosine.Biological Value of Protein: Biological value of protein is the percentage of a proteinnitrogen that is absorbed and available for use by the body for growth and maintenance.Proteins are functionally divided into complete, partially complete and incomplete 10
  13. 13. proteins. A complete protein contains all essential amino acids in relatively the sameamounts as human beings require to promote and maintain normal growth. (eg) Proteinderived from animal foods. A partially complete protein contains sufficient amounts ofamino acids to maintain life but fail to promote growth. (eg) Gliadin in wheat. Incompleteproteins are incapable of replacing or building new tissue and cannot support life orgrowth. (eg) Protein in Wheat germ.Food sources of dietry protein Food Stuff Protein %1 Meat, fish and liver 18 – 202 Eggs 143 Milk powder, full fat 264 Milk powder, skimmed 335 Cheese 18 – 206 Pulses 18 – 247 Nuts and oilseeds 18 – 268 Soyabean 35 – 409 Cereals and millets 6 – 1210 Tender legumes, green peas, cow peas 7–811 Potato 212 Green leafy vegetables 2-6Source : Swaminathan. M. 1986. Principles of Nutrition and Dietetics.Functions of ProteinProteins form a major part of total body structures and they participate in many activitiesin our body. The major functions of protein in our body can be listed below1. Build and repair body tissues: Proteins form integral parts of most body structuresuch as skin, tendon, membranes, muscles, organs and bones. They support the growthand repair of body tissues.2. Enzymes: (eg) Lipase helps to breakdown fat and sucrase breaks down sugar.3. Hormones: Regulate body process.4. Antibodies: Inactivate foreign invaders thus protecting the body against disease.5. Fluid & electrolyte balance: Proteins help to maintain the volume and composition ofbody fluids. 11
  14. 14. 6. Acid-base balance: Proteins help maintain the acid-base balance of the body fluids byacting as buffers.7. Energy: Proteins provide fuel for the body’ s energy needs [4 KCal/gm].8. Storage: Proteins help to store iron and copper.9. Homeostasis: Proteins maintain normal osmotic balance among body fluids.10. Transport: proteins (eg) Haemoglobin, lipoprotein These type of proteins carrynutrients to the tissues. eg lipoprotein carry lipids, haemoglobin transports oxygen.11. Contribute to sensory & physical properties of food: Proteins impart colour,flavour, odour and texture to foods.Digestion, Absorption and Utilization of proteinsDigestionProteins taken in the diet are digested to amino acids in the stomach and small intestine.Gastric juice contains enzymes pepsin which digests protein in acid medium. Ithydrolyses proteins to polypeptides. Dietary Protein Pepsin Polypeptides In the smallintestine, pancreatic and intestinal juices contain proteolytic enzymes. Pancreatic juicecontains trypsin, chymotrypsin and carboxyl peptidase.They hydrolyse large protein molecule to smaller polypeptide.Proteins Trypsin and Chymotrypsin Peptides + Amino acidsPeptides Carboxy peptidase Aminoacids Amino PeptidaseIntestinal juices contains polypeptidases & dipeptidases which hydrolyse polypeptide &dipeptide to individual amino acids. There are several peptidases acting on differentproteins. When undigested protein enter large intestines, bacteria causes nitrification ofproteins leading to foul smelling flatus.Dipeptides Dipeptidase Amino acidsTripeptides Tripeptidase Amino acidsProteins are mainly absorbed in the form of amino acids. Amino acids are absorbed byactive transport mechanism in the intestinal cells. Sometimes whole protein may be 12
  15. 15. absorbed by the mechanism of pinocytosis. Absorbed amino acids pass into the portalblood and reach liver where they are converted to proteins. Other amino acids aretransported through general circulation and are utilized for protein synthesis in thetissues.Utilization of proteins in the bodyThe amino acids from digested proteins are absorbed rapidly into the blood and passedonto different tissues to meet their needs. Some non-essential amino acids are synthesizedin the liver and also released into the circulation. The amino acids released by hydrolysisof tissue proteins are also added to the amino acid pool in the body.Requirements1.0 g/kg/day is the safe level of intake in terms of dietary proteinEffects of DeficiencyDeficiency of energy and protein commonly occur in developing countries like Nigeria.This is manifested as Marasmus and Kwashiorkor. Protein Energy Malnutrition (PEM) isa term used to describe clinical disorders resulting from varying degrees of protein andenergy deficiency. Kwashiorkor is due to quantitative and qualitative deficiency ofprotein in diet in which energy intake is adequate. Marasmus is due to continuedrestriction of energy intake. PEM is prevalent in all parts of the World and in all ages. 13
  16. 16. 1.3.3 LIPIDSLipids more commonly known as fats and oil are integral part of our food. They areinsoluble in water but soluble in organic solvents. They occur in both plant and animals.Lipids are a concentrated source of energy.ClassificationLipids are classified into simple, compound and derived lipids which are furthersubdivided as follows a. Simple lipids: Fats and Oils are included in this type. At room temperature, oilsare liquids and fats are solids. Fats and oils contain esters of fatty acid and glycerol, aform in which lipids are present in food. Other simple lipids are waxes. b. Compound lipids: They are esters of fatty acids containing phosphorouscarbohydrate or protein. Phospholipids contain a phosphoric acid in addition to thealcohol and fatty acids. Glycolipids contain a fatty acid, carbohydrate and a nitrogenousbase. Phospholipids and glycolipids form part of the cell membrane and the nervoussystem. Lipoproteins are macromolecular complex of lipids with proteins. c. Derived lipids: These are substances liberated during hydrolysis of simple andcompound lipids which still retain the properties of lipids. The important members of thisgroup are sterols, fatty acids and alcohol. Sterols: Sterols are solid alcohols and form esters with fatty acids. In nature theyoccur in the free state in the form of esters. Based on their origin sterols are classified ascholesterol (animal origin) and phytosterol (in plants). Cholesterol is a complex type oflipid that is regularly synthesised by and stored in the liver. It is present in all animalproducts. Fatty acids: Fatty acids are the main building blocks of fat. They have a methylgroup (CH3) at one end and a carboxyl group (COOH) at the other end with a chain ofcarbon and hydrogen atom in the middle. They have a basic formula CH 3(CH2)n COOH.Where ‘n’ denotes the number of carbon atoms which may vary from 2 to 2l.Fatty acids can be classified either as Saturated Fatty Acids(SFA) or Unsaturated FattyAcids (UFA). 14
  17. 17. Essential and Non – Essential fatty acidEssential fatty acid (EFA) are those which cannot be synthesized by the body and need tobe supplied through diet. E.g Linolenic acid, linoleic acid and arachidonic acid.Non-essential fatty acids are those which can be synthesized by the body and which neednot be supplied through the diet. E.g Palmitic acid, oleic acid and butyric acid.Functions of LipidsLipids perform several important functions:1) They are the concentrated fuel reserve of the body. When one gram of fat is oxidized ityields 9 kilocalories.2) Lipids are the constituents of cell membrane structure and regulate the membranepermeability.3) They are essential for the digestion, absorption and utilization of fat soluble vitaminslike Vitamin A, D, E and K.4) Lipids are important as cellular metabolic regulators (Steroid hormones andprostaglandin).5) Lipids protect the internal organs serving as insulating materials.6) As compounds of the mitochondria membranes, lipids (phospholipids) participate inelectron transport chain.7) Fat imparts palatability to the diet and slows stomach emptying time, thus giving afeeling of fullness. This delay of onset of hunger is called ‘satiety value’ of fats.8) The calories in fat spare the proteins from being oxidized for energy.9) Fat deposited in the adipose tissue serves as reserve source of energy during starvation.It acts as an insulator conserving the body heat. Essential fatty acids which are derivedlipids perform important functions in our body.Functions of essential fatty acids:1) Maintenance of the function and integrity of cellular and subcellular membrane.2) Regulation of cholesterol metabolism by transporting it between the blood and bodytissues. 15
  18. 18. 3) Acts as precursor of hormone like – prostaglandin which aid in regulating vascularfunction and help relieving pain and inflammation.4) Delays blood clotting time.Food SourcesFoods in general contain two types of fat namely “visible fats” and “invisible” or“hidden” fats. Visible fats:Visible fats are fats extracted from the following sources.a. Oil seeds : coconut, corn, cornseed, groundnut, mustard, palm, rice bran, safflower,seasame, soyabean, sunflower and hydrogenated vegetable oils.b. Animal fats: Butter and Ghee.c. Fish oils: Shark and cod liver oils. Invisible or hidden fats:Invisible or hidden fats are those which form an integral part of foods and are thereforenot visible. It includes the fats present in the cells and cell walls and cell membranes ofboth plant and animal tissues.Almost everything we eat as listed below carries some invisible fats.a) Plant food – Cereals, millets, vegetables, spices, nuts and oil seeds, coconut, avacado.b) Animal food – Milk and milk products (curd, cream, cheese), flesh foods, (mutton,beef, pork, chicken) organ meats (brain, liver, kidney), fish, shrimp, prawn.Sources of Saturated Fat:Saturated fat is resistant to oxidation even at frying temperatures. Examples area) Plants – coconut oil. Hydrogenated vegetable oils. Palm kernel oil.b) Animals – Butter, ghee, fats from flesh foods and organ meats.Sources of Unsaturated Fat:Unsaturated fats and oils include mono and poly unsaturated fatty acids (MUFA andPUFA) in various proportions: 16
  19. 19. a) Plant sources: All common vegetable oils with the exception of coconut oils arepredominantly unsaturated. The invisible fats present in nuts and oilseeds, cereals, pulsesand legumes, roots and tubers, vegetables, spices and fruits. In most plant foods andvegetable oils linoleic acid is the predominant PUFA, but mustard and soyabean oils,legumes/pulses. Fenugreek leaves, and green leafy vegetables are good sources of alphalinolenic acid.b) Animal sources: The muscles (lean meat) of flesh foods, unlike the depot fatsurrounding the tissues is mainly composed of cholesterol esters and phospholipids, bothof which have a high proportion of long chain n-6 PUFA which are otherwise formed inthe body from linolenic acid. Arachidonic acid is found in animal and human cells. Fishand fish oils provide long chain n–3 PUFA.CholesterolCholesterol is a constituent of animal foods but is absent in plants. Vegetable oils do nothave cholesterol. In human diets, cholesterol is obtained from ghee, butter, cheese, milk,curd, egg, flesh foods, organ meats, fish and prawns. Most animal foods are good sourcesof both cholesterol and fatty acids.HydrogenationHydrogenation (addition of hydrogen at double bonds) converts liquid oils into semisolidor solid fats. During hydrogenation, linoleic and alpha linolenic acid present in the oilsare converted to trans fatty acids and saturated fatty acids.Also, the monounsaturated fatty acids are converted to saturated fatty acids.Hydrogenated fats were designed to imitate ghee. It is used to prepare processed foodslike biscuits and cakes. 17
  20. 20. Digestion Absorption and UtilizationDigestionIn the mouth: Fat digestion starts in the mouth with hard fats beginning to melt whenthey reach body temperature. The salivary glands at the base of the tongue release alipase enzyme which digests fat to a less extent in adults.In the stomach: In the stomach fat floats as a layer above the others components ofswallowed food. As a result little fat digestion takes place.In the small Intestine: When fat enters the small intestine, the hormone cholescystokininsignals the gall bladder to release bile. Bile emulsifies fat and also provides an alkalinemedium for the action of pancreatic lipase and intestinal lipase. The triglycerides areacted upon by these lipases and hydrolyzed to monolycerides and fatty acids.The cholesterol esters are hydrolyzed to give cholesterol and fatty acids.Triglycerides Monoglyceride + fatty acidsCholesterol esters Cholesterol + fatty acidsAbsorption and UtilizationSmall molecules of digested triglycerides (glycerol, short & medium chain fatty acids)can diffuse into intestinal cells and are absorbed directly into the blood stream.Larger molecules (Monoglycerides, long chain fatty acids) merge into sphericalcomplexes known as miscelles. The lipid contents of the miscelles diffuse into theintestinal cells. Once inside the monoglycerides and long chain fatty acids arereassembled to new triglycerides.Within the intestinal cells the new triglycerides and larger lipids like cholesterol andphospholipids are placed into transport vehicle called chylomicrons.The intestinal cells then release chylomicrons into the lymphatic system. The lymphcirculation empties into the thoracic duct which inturn enter the subclavian vein andsubsequently into the blood stream.The blood transport lipids to the rest of the body and cells absorb them and utilize forenergy. This breakdown of fat to yield energy is called lipolysis. 18
  21. 21. Majority of lipids enter via the lymph to the liver where the protein and lipid (cholesterol,triglycerides) are bound together to form lipoproteins.There are four types of lipoproteins, they are:i) chylomicrons,ii) very low density lipo protein (VLDL)iii) low density lipo protein (LDL) andiv) high density lipo proteins (HDL).Chylomicrons, VLDL and LDL serve to transport and deposit lipids from the intestineand liver to the tissues for absorption. Low-density lipoprotein, which has the highestcholesterol fraction favours lipid deposition in tissues including blood vessels and hencetermed ‘bad’ cholesterol. HDL cholesterol removes the lipids from the tissues andtransports it back to liver for disposal, hence it is termed as ‘good cholesterol’. A highlevel of LDL cholesterol indicates a high risk of cardiovascular disease. Apart fromlipoproteins, triglycerides, cholesterol and phospholipids are synthesized in the liver. Thisis called lipogenesisEffects of DeficiencyDeficiency of fat in the diet causes the deficiency of essential fatty acids (EFA).Deficiency of essential fatty acids leads to cessation of growth. It also results in flakyskin, development of itchy sores on the scalp. A common disorder in adults and childrenis phrynoderma or toad skin. The condition is characterized by the presence of hornyeruptions on the posterior and lateral aspects of the limbs on the back and buttocks.Phrynoderma is cured rapidly by the administration of linseed or safflower seed oil richin EFA. Infants fed on a EFA deficient diet develop irritation and changes in the skinwithin a few weeks, the skin changes appear as dryness and desquamation with oozing inthe folds. Diarrhoea may also occur, supplementation of the diet with linoleic acid helpsto restore the skin to normal condition (Sheila et al., 2004).. 19
  22. 22. MINERALS AND VITAMINSUntil the middle of the nineteenth century, the importance of minerals and vitamins wasnot known. It was observed that carbohydrate, fat, protein alone were incapable ofpromoting and sustaining growth. Hence scientists attempted to find out the “missingelements”, namely minerals and vitamins which are essential for growth andmaintenance.1.3.4 MINERALSEssential minerals which are inorganic substances are classified as macro andmicronutrients based on the amount needed by humans per day.Macrominerals are those which are vital to health and that are required in the diet bymore than 100mg per day and those required in the diet less than 20mg per day are calledmicrominerals or trace minerals. The essential macrominerals are Calcium, Phosphorous,Magnesium, Sulphur, Potassium and Chloride. Important microminerals of relevance inhuman nutrition are Iron, Zinc, Copper, Sodium, Cobalt, Fluoride, Manganese,Chromium, Iodine and Molybdenum.Macrominerals- 2 examplesCalcium and PhosphorusCalcium is an essential element required for several life processes. The requirements ofCalcium and Phosphorous are considered together as their function and requirement areclosely linked. Over 99% of the Calcium and Phosphorous is present in the bones and theremaining 1% in the body fluids.The Calcium and Phosphorous are present in the ratio of 2:1 in our body. In the skeletalsystem Ca and P is present in the form of hydroxyapatite crystals. Hydroxyapatite is acompound made up of calcium and phosphate that is deposited into the bone matrix togive it strength and rigidity.Functions:1. Bone formation: The major mineral ions of the bone are Calcium, Phosphorous andMagnesium. For proper calcification of bones, (deposition of minerals on the bonematrix) which occurs during the growth, adequate supply of these minerals is essential. 20
  23. 23. 2. Tooth formation: - C and P together are essential for dentin and enamel formation.3. Physiological Process: -a. C is essential for the clotting of blood as it is required for prothrombin activation.b. C regulates the permeability of the capillary walls and ion transport across the cellmembranes.c. It is essential for the contraction of the heart and skeletal muscle.d. Ca regulates the excitability of the nerve fibres.e. Ca acts as an activator for enzymes such as rennin and pancreatic lipase.4. Phosphorous is essential for the storage and release of ATP molecules.5. Phosphates act as buffers to prevent changes in acidity of the body fluids.6. Phoshpolipids are major components of cell membrane and intra cellular organelles.7. In the DNA and RNA phosphate is an essential part of the nucleic acids.Food sourcesCereals contains large amounts of calcium. Gingely seeds, cuminseeds, poppy seeds,drumstick leaves are good sources of calcium. Milk and milk products are good sourcesof calcium and phosphorous. Only 20 – 30 % of the calcium in the diet is absorbed,which is facilitated by Vitamin–D. All foods contain significant amounts of phosphorous.DeficiencyCalcium related health problems occur due to inadequate intake, improper absorption orutilization of calcium.Osteoporosis: Osteoporosis is a condition found primarily among middle aged andelderly woman, where the bone mass of the skeleton is diminished.It is a condition of multiple origin. It results due to the following reasons:(i) Prolonged dietary inadequacy(ii) Poor absorption and utilization of calcium(iii) Immobility(iv) Decreased levels of oestrogen in post-menopausal women.(v) Hyper parathyroidism(vi) Vitamin – D deficiency 21
  24. 24. Osteomalacia – is a condition in which the quality but not the quantity of bone isreduced. This condition results from deficiency of Vitamin–D.Tetany - Tetany occurs when Calcium in the blood drops below the critical level. Thereis a change in the stimulation of nerve cells resulting in increased excitability of the nerveand uncontrolled contraction of the muscle tissue. Hence Calcium and Phosphorous ratioin the diet should be maintained at 1:1 for proper utilization of Calcium in the body.Microminerals -1 exampleMicrominerals are also known as trace elements. However only the deficiency of few ofthese elements is observed in humans. Iron and Iodine deficiencies are wide spread whiledeficiencies of Cu, Zn, Cr and Se have been reported in recent years.IronThe total body iron is 4g in adults. Iron exists in a complex form in our body. Present asa) Iron porphyrin compounds – hemoglobin in RBC, myoglobin in muscle.b) Enzymes – (eg) peroxidases, succinase dehydrogenase and cytochrome oxidase.c) Transport and storage forms: - (eg) transferrin and ferritin.FunctionsThe chief functions of iron in the body are:1. Iron forms a part of the protein – haemoglobin which carries oxygen to different partsof the body.2. It forms a part of the myoglobin in muscles which makes oxygen available for musclecontraction.3. Iron is necessary for the utilization of energy as part of the cells metabolic machinery.4. As part of enzymes iron catalyzes many important reactions in the body. Examples area) Conversion of beta carotene to active form of Vitamin Ab) Synthesis of carnitine, purines, collagen and neuro transmiters.c) Detoxification of drugs in the liver. 22
  25. 25. Food SourcesThe iron present in food can be as haem and non-haem iron depending upon the sourcefrom which it is obtained. Haem iron – is obtained from animal tissues, non-heam iron –is obtained from plant foods.Sources of non-haem iron are green leafy vegetables, dried fruits and jaggery. Liver, fish,poultry, meat, eggs dates are good sources of haem iron. Haem iron is absorbed andutilized better than the nonhaem iron. Iron absorption from Nigerian diets is only 3percent as it is mainly cereal based diet.DeficiencyDietary iron deficiency leads to nutritional anaemia. Nutritional anaemia is defined as thecondition that results from the inability of the erythropoetic tissue to maintain a normalhaemoglobin concentration. Anaemia occurs when the haemoglobin level falls below 12gm /dl in adult man and woman. During pregnancy haemoglobin level below 11 gm /dl istermed anaemia. This is the common form of anaemia affecting women in reproductiveyears, infants and children which is mainly due to poor intake and absorption. Irondeficiency anaemia is wide spread in our country.Nutritional anemia is manifested as1. Reduced Haemoglobin level. (less than 12 g /dl)2. Defects in the structure, function of the epithelial tissues3. Paleness of skin and the inside of the lower eyelid is pale pink4. Finger nails becoming thin and flat and eventually (spoon shaped nails) koilonychiadevelops.5. Progressive untreated anaemia results in cardiovascular and respiratory changesleading to cardiac failure. The general symptoms include lassitude, fatigue,breathlessness on exertion, palpitations, dizziness, sleeplessness, dimmness of vision, andincreased susceptibility to infection. 23
  26. 26. 1.3.5 VITAMINSVitamins are organic substances present in small amounts in food, they are required forcarrying out vital functions of the body. They are involved in the utilization of the majornutrients like proteins, fats and carbohydrates.Though needed in small amounts, they are essential for health and well being of the body.When these Vitamins were discovered on the basis of their function and before theirchemical nature were elucidated, they were designated as A,B,C,D or in terms of theirmajor functions like, antineuritic, antirichitic Vitamins. Vitamins are classified based ontheir solubility as fat soluble and water soluble vitamins.Water soluble vitamins are not accumulated in the body, but are readily excreted whilefat soluble vitamins are stored in the body. For this reason excessive intake of fat solublevitamins, especially Vitamin A and D can prove toxic. Excessive intake leads to thecondition called hypervitaminosis.Functions, food sources, requirements and effects of deficiencyFat soluble vitamins: 2 ExamplesVitamin AVitamin A was the first fat soluble vitamin to be recognized. Three forms of Vitamin Aare active in the body, retinol, retinal and retinoic acid. They are collectively called asretinoids.Beta carotene is the provitamin of Vitamin A. Provitamins are substances that arechemically related to a vitamin but must be changed by the body into the active form of 24
  27. 27. the vitamin. Vitamin A in the diet comes in two forms. Retenoids (preformed Vitamin A)and carotenoids. Vitamin A is present in vegetable foods which contain yellow pigmentcalled carotenes. It was isolated from carrots hence called carotenoids which areprovitamins of Vitamin A.Functions1) A well understood function of retinol is in the visual process. The retina of the humaneye contains two distinct photo receptors of which one is sensitive to light intensities.Vitamin A is essential for the formation of rhodopsin and normal functioning of the retinafor clear vision in dim light. Lack of Vitamin A leads to impaired adaptation to darkness.2) Participates in protein synthesis and cell differentiation and thereby maintaining thehealth of the epithelial tissues and skin.3) Supports reproduction and growth4) Vitamin A regulates the antibodies and cellular immune response. It is essential formaintaining the epithelial tissue which is the first line of defence against invadingmicroorganism.5) Beta carotene acts as an antioxidant capable of protecting the body against disease likecancer, cardiovascular diseases and cataract.SourcesVitamin A in the human diet exist as retinol or as retinal or beta carotene which has to beconverted to Vitamin A. Foods of animal origin contain retinol. Plant sources are rich inBeta carotene. Only one third of the dietary beta Carotene is absorbed.Beta Carotene from green leafy vegetables is well utilized than from carrots and papayas.Good sources of Vitamin A are sheep liver, butter, ghee, egg, milk, curds, liver oils ofshark and halibut. Good sources of beta carotene are green leafy vegetables, mango,papaya, carrot and jack fruit.Effects of DeficiencyDeficiency of Vitamin A is Nutritional blindness is an important public health problemamong young children. Night blindness is an early symptom of Vitamin A deficiency.The individual cannot see in dim light. This can be corrected with adequate supply of 25
  28. 28. Vitamin A. In the absence of adequate Vitamin A intake the outer lining of the eye ballloses its usual moist, white appearance and becomes dry and wrinkled called xerosis.This condition is followed by raised muddy dry triangular patches on the conjunctivacalled the bitots spots. Redness and inflammation of the eye and gradual loss of visionmay follow. The central portion of the eye loses its transparency and becomes opaqueand soft if not treated and leads to total blindness termed Xeropthalmia. Xeropthalmiaencompasses all ocular manifestations of Vitamin A deficiency.Increased susceptibility to infection occurs because the mucous membrane liningbecomes dry and rough which is easily invaded by the micro – organism.HypervitaminosisIntake of large amount of Vitamin A for prolonged periods can lead to toxic symptomswhich include irritability, headache, nausea and vomiting.Vitamin DVitamin D can be synthesized in the body in adequate amounts by simple exposure tosunlight, even for 5 minutes per day is sufficient. It is essential for bone growth andcalcium metabolism. It acts as a hormone in the body by facilitating calcium absorptionand deposition in the bone.Functions1. Vitamin D helps in the absorption of calcium and phosphorous by increasing thesynthesis of calcium binding protein.2. Vitamin D helps to maintain the calcium and phosphorous levels in the body bystimulating,a) Absorption in the gastro intestinal tract.b) Retention by the kidney3. Vitamin D helps in deposition of calcium in the bones. The bones grow denser andstronger. 26
  29. 29. Food SourcesThe Vitamin D content of food sources from animals varies with the diet, breed andexposure to sunlight of the animal. The good sources of Vitamin D are cod liver oil,shrimp, liver, butter, yolk, cheese, milk, spinach and cabbage.RequirementsOnly in those cases where the Vitamin D requirement is not met due to inadequateexposure to sunlight 400 μg/day of Vitamin D is recommended.DeficiencyDeficiency of Vitamin D leads to decreased absorption of calcium which is manifested asmuscular tetany, rickets in children and osteomalacia in adults.Due to faulty calcification of bones the following derfomities is manifested in childrenwhich is called rickets. It is a disease in which there is weakness and abnormalities inbone formation. Rickets primarily affects children.Manifestationsa) faulty deposition of calcium on the bones.b) Bowing of legsc) Enlargement of ends of long bonesd) Deformities of ribs – beading of ribse) Delayed closing of frontanelf) Slow erruption of teeth.g) Malformed, decay – prone teethOsteomalacia in AdultsOsteomalacia is a condition where the quality of the bone is reduced. It occurs in womenwho are not exposed to sunshine and who have depleted mineral reserves resulting fromsuccessive pregnancies and prolonged lactation.Osteomalacia is associated with low phosphorous level but low blood calcium level is themost frequent cause.The following symptoms occur1. softening of the bones 27
  30. 30. 2. deformities of the limbs, spine, thorax and pelvis3. demineralization of the bones4. pain in pelvis, lower back and legs5. frequent bone fractures.HypervitaminosisAs in the case of Vitamin A intake of excessive amounts of Vitamin D leads to toxicsymptoms which include irritability, nausea , vomiting and constipation.Water soluble Vitamins: 2 ExamplesVitamin C (Ascorbic Acid)The chemical name for Vitamin C is ascorbic acid. It was discovered in 1747 by theBritish physician Lind who showed that citrus fruit juices prevented and cured scurvy.Functions :1. Ascorbic Acid is essential for formation of cement substances and collagen which isfound in blood vessels teeth and bones.2. It helps in the biosynthesis of non-essential amino acids (eg) hydroxy proline, tyrosin.3. It is required for absorption of iron as it reduces ferric to easily absorbed ferrous form.4. Vitamin C is essential for the formation of collagen a major structural protein5. It is required for wound healing because it helps in the formation of connective tissue.6. Required for carnitine synthesis which aids in the transport of fatty acids in cells.7. Vitamin C is essential for the synthesis of norepinephrine a neurotransmitter.8. It activates hormones (eg) growth hormone, gastrin releasing peptide, calcitonin,gastrin oxytocin.9. Drug detoxifying metabolic systems in the body require Vitamin C for its activity.10. Vitamin C is an excellent anti-oxidant. It combines with free radicals oxidizing themto harmless substances that can be excreted.Food Sources: guava, cashew fruit, cabbage, bitter gourd, oranges, tomatoes are goodsources of ascorbic acid. Cereals and pulses are poor sources. Vitamin C content ofpulses increases on germination. 28
  31. 31. Effects of Deficiency: Prolonged deficiency of ascorbic acid produces a diseasecondition called as ‘scurvy’ in both infants and adults.Infantile scurvy:There is loss of appetite, failure to gain weight, irritability, palor, defective growth ofbones. Haemorrhage occurs under the skin. There is defective formation of teeth andgums are swollen. The ends of the ribs become prominent resulting in beaded appearancecalled scorbutic rosary.Adult Scurvy:1. General manifestations are fever, susceptibility to infection, and delayed woundhealing.2. Anaemia: Microcytic hypochromic anaemia develops due to failure of absorption ofiron.3. Gums become spongy and bleed easily. Gums become swollen and ulcerated.4. The blood vessels become fragile and porous due to defective formation of collagen.Joints become swollen and tender.5. Clinical symptoms appear when total body pool of ascorbic acid decreases. Skinbecomes rough and dry. There are small petechial hemorrhages around hair follicles.Vitamin B1 (Thiamine)Thiamine is known as Vitamin B1. Functions1. Thiamine is converted to thiamine pyrophosphate (TPP), which is an important coenzyme in the carbohydrate metabolism.2. It is involved in transmission of nerve impulses across the cells3. Thiamine as TPP is an essential cofactor for the conversion of amino acid tryptophanto niacin.Sources:Yeast, whole wheat, millets, hand pounded rice, parboiled rice are good sources ofthiamine. The bran contains most of the thiamine in the cereals. Gingelly seeds,groundnut, soyabean, cashewnuts, organ meats, pork, liver and eggs supply thiamine. 29
  32. 32. RequirementsThiamine is involved in the carbohydrate metabolism. Its requirement is related to energyderived from carbohydrate. An allowance of 0.5 mg per 1000 Kcal for adults and forinfants 0.3 mg/1000 Kcal is suggested.Effects of DeficiencyDeficiency of thiamine is associated with low calorie intake. Severe deficiency ofthiamine produces a disease known as beri – beri.It is manifested asa. Dry beri – berib. Wet beri – beric. Infantile beri – beria. Dry beri – beriThere is loss of appetite, tingling numbness and burning sensation in hands and feet. Calfmuscles are tender. Knee and ankle jerks are sluggish.In later stages complete loss of sensation in hands and legs occur. It is characterized byfoot and waist drop. Mental depression and confusion occurs.b. Wet beri – beriIn this case there is enlargement of heart and the cardiac output is high. Oedema oraccumulation of fluid in legs, face and trunk is observed. palpitations are marked.c. Infantile beri – beriIt occurs in first few months of life if the diet of the mother is deficient in thiamine.Symptoms are restlessness, sleeplessness, constipation, enlargement of the heart andbreathlessness. 30
  33. 33. 1.3.6 WATERWater makes up about 70% of the weight of human. For each 100kcal of energymetabolized, animals can manufacture about 12g of water. Fresh and clean tap water isadequate as water source for humans although, municipal water supply do sometimescontain dissolved minerals, hydrocarbons, chlorine and fluorine. Water (moisture) is thepredominant constituent in many foods.Water is vital for human existence. We can live without food for extended periods oftime, but without water will result in death. Water is colourless, calorie less compound ofhydrogen Water is closer being a universal solvent than any other compound with achemical formula of H2O.Water is the largest single compound of the body and it is distributed as follows.Total body water content is mainly determined by total amount of salt in the body. Saltand water concentration in the body is controlled by the kidneys. 31
  34. 34. Functions of Water1. It is an essential constituent of all the cells of the body and the internal environment.2. Serves as a transport medium by which most of the nutrients pass into the cells andremoves excretory products.3. Water is a medium for most biochemical reactions within the body and sometimes areactant.4. It is a valuable solvent in which various substances such as electrolytes, non –electrolytes, hormones, enzymes, vitamins are carried from one place to another.5. Plays a vital role in the maintenance of body temperature. Heat is produced when foodis burnt for energy. Body temperature must be kept at 80º - 108º Fahrenheit for higher orlower body temperature will cause death. Body heat is lost through the skin, lungs, urineand faeces.6. It forms a part of fluids in body tissues; (eg) the amniotic fluid surrounds and protectsthe foetus during pregnancy.7. Saliva is about 99.5 percent water. In healthy individuals it makes swallowing easierby moistening the food.8. Water helps in maintaining the form and texture of the tissues.9. Water is essential for the maintenance of acid base and electrolyte balance. It should benoted that pure water consists of hydrogen ion (H+) and hydroxyl ion (OH-).Substances dissolve in water as ions with positive and negative charge. They are calledelectrolytes. The common electrolytes in our body are sodium, potassium and chloride.Changes in electrolyte balance causes accumulation or depletion of water in intracellularand extra cellular fluid.The balance between the positively and negatively charged ions is essential for waterflow and maintain osmolarity between the cells. This is called electrolyte balance. Acidbase balance is the dynamic state of equilibrium of hydrogen ion concentration. When pHfalls below 7 it is termed acidity and when it increases above 7 it is termed alkalinity.Extremes of both cases results in death. The pH of the body should be maintained nearneutrality. Enzymatic action depends on the pH. The digestion, absorption and utilization 32
  35. 35. of nutrients are dependent on pH. Most body fluids are near neutral with the exception ofgastric juice. The pH value of some solutions are given below:Acid0 – Hydrochloric acid12 – Gastric juice3 – Vinegar, orange juice4 – Grapes5 – Bread, coffeeNeutral 6 – Urine7 – Pure water, eggs, blood8 – Sea water14 – Sodium hydroxideAlkali10. Water forms good source of macro minerals like Calcium, Magnesium, Fluoride, Ironand Iodine.RequirementsRequirements of water varies withclimate, dietary constituents, activitiesand surface area of the body. As a rule aperson should take enough water toexcrete about 1200 –1500 ml of urineper day. In tropics because of greaterwater loss through perspirationincreased water intake is required tomaintain urine volume. Normal intakeof water ranges between 8 – 10 glasses Source : Susan.R.Holman,1987. Essentials ofper day. Nutrition for the Health Professionals. 33
  36. 36. Daily Water InputIn tropical countries like Nigeria the daily water input amounts to 2400 – 3000 ml ofwater through food, as fluid drinks and as metabolic water.1. As fluid drinks – water, tea, coffee, milk soups 1500 - 1750 ml2. Water intake through solid food 600 - 900 ml3. Oxidation of carbohydrate, fat, proteins (metabolic water) 300 - 350 ml Total 2400 - 3000 mlDaily output of water1. Urine 1200 – 1500 ml à (kidney)2. Perspiration 700 – 900 ml à (Skin)3. Respiration 400 ml à (lung)4. Faeces 100 – 200 ml à (intestine) Total 2400 – 3000 mlTherefore the water intake and output is fairly kept constant. This is called water balance.The water equilibrium is maintained by kidneys, lungs, intestine and pituitary gland. Thewater balance coordinates with both electrolyte and acid base balance.Causes and Effects of DehydrationCauses: When water is constantly lost from the body as in severe vomiting, diarrhoea,excessive sweating or excessive urine formation due to treatment with diuretics, the totalwater content of the body is reduced. Extra-cellular and intra-cellular fluid decreasesleading to dehydration.Effects of dehydration1. Tongue is dry.2. Pinch test is done by raising and releasing the skin. Slow return of skin to originalposition indicates decreased ECF.3. Decrease in plasma volume reduces cardiac output and may lead to cardiac failure.Prevention of DehydrationDehydration can be prevented by taking sufficient amounts of water as fluids. Thecorrection of dehydration is called rehydration. 34
  37. 37. Oral rehydration therapyIt is the administration of fluid to prevent or correct dehydration.Oral rehydration saltWHO, UNICEF formula consist of the NaCl – 3.5 g, NaHCO 3 – 2.5 g, KCl – 1.5g andglucose - 20 g to be dissolved in one litre of potable drinking water.The Glucose present aids in the absorption of sodium chloride and potassium chlorideapart from giving energy. This mixture is administered through the oral route at frequentintervals until the normal state is attained.Potable water is that water which is safe and wholesome. It should be:a. free from pathogenic agentsb. free from harmful chemical substancec. pleasant to taste; free from colour and odourd. usable for domestic purpose. 35
  38. 38. CHAPTER TWO2.0 HEALTHY NUTRITIONHealth is defined by the World Health Organization (WHO) as the “State of completephysical, mental and social well-being and not merely the absence of disease orinfirmity”. To maintain good health and nutritional status one must eat a balanced food,which contains all the nutrients in the correct proportion.The essential requisites of health would include the following:1. Achievement of optimal growth and development, reflecting the full expression ofone’s genetic potential.2. Maintenance of the structural integrity and functional efficiency of body tissuesnecessary for an active and productive use.3. Mental well-being4. Ability to withstand the inevitable process of aging with minimal disability andfunctional impairment.5. Ability to combat diseases such as– resisting infections (immunocompetence)– preventing the onset of degenerative diseasesA healthy nutrition, help one get the right balance of vitamins, minerals, and othernutrients have plenty of energy and handle stress better, prevent and control healthproblems. There is also strong evidence that, as a rule, the closer to nature one eats, thefewer calories it will take for satiety, the reason is that processed foods often have lowamounts of fiber and water, ‘’high ratio of calories to nutrients’’, and a mixture of tastefrom added sugar, salt and flavorings that overly stimulate the appetite center in thehypothalamus. But that is not the case with clean foods, which has lots of fiber and fluid,a high ratio of nutrient to calories, and free of added flavors, all of which send signals ofsatiety to the brain before one consumes too many calories (Davids, 2010). “Vitality andbeauty are gifts from nature for those who live according to its laws” (Leonardo DaVinci,2002). A proper nutrition and food habits that integrate culture and tradition can add 36
  39. 39. years to life, especially a better quality of life in later life through the reduction of risk ofmany chronic conditions related to nutrition. Micronutrients such as vitamins, minerals,antioxidants and others that affect body regulation depend on the adequacy and variety onthe diet we consume and this can be met by making a good balanced dietary choices.2.1 DIETARY GUIDELINESDietary Guidelines attempt to answer the question, “What should we eat to stay healthy?”Specifically, the Guidelines provide advice for healthy people about food choices thatpromote health and reduce the risk of disease.Dietary Guidelines for the Nigerian Population (FAO, 2006) • Good Nutrition • No single food by itself (except breast milk) provides all the nutrients in the right amounts that will promote growth and maintain life. To achieve good nutrition, therefore, it is necessary to consume as wide a variety of foods as possible from the age of 6 months o Infants (0–6 months) • Start exclusive breast-feeding immediately after birth and continue for 6 months • There should be no bottle-feeding o Infants (7–12 months) • Continue breast-feeding • Introduce complementary feeds made from a variety of cereals, tubers, legumes, fruits, animal foods and give with cup and spoon o Toddlers (13–24 months) • Continue to breast-feed until child is 2 years • Give enriched pap or mashed foods twice daily • Give family diet made soft with less pepper and spices • Give fruits and vegetables in season 37
  40. 40. o Children (25–60 months)• Give diet that contains a variety of foods in adequate amounts.• Add palm oil or vegetable oil to raise the energy level of complementary foods Gradually increase food intake to 4–5 times daily as baby gets older• Provide dark green leafy vegetables, yellow/orange colored fruits, citrus fruits, cereals, legumes, tubers and foods of animal origin.• Limit the consumption of sugary food• Continue feeding even when child is ill o School-aged children (6–11 years)• Give diet that contains a variety of foods in adequate amounts• Encourage consumption of good quality snacks, but limit the consumption of sugary snacks o Adolescents (12–18 years)• Consume diet containing a variety of foods• Most of the energy should be delivered from roots/tubers, legumes, cereals, vegetables, and less from animal foods• An increase in total food intake is very important at this stage, so is the need to enjoy family meals• Snacks especially pastry and carbonate drinks should not replace main meals. If you must eat out, make wise food choices• Liberal consumption of whatever fruits that is in season should be encouraged• Females need to eat more iron-containing foods like meat, fish, poultry, legumes. o Adults (male and female)• Total food intake should take into consideration the level of physical activity. Individuals who do manual work need to consume more food than those who do sedentary work• Limit the fat intake from animal foods 38
  41. 41. • Diet should consist of as wide a variety of foods as possible for example, cereals, legumes, roots/tubers, fruits, vegetables, fish, lean meat, local cheese (wara)• Limit intake of salt, bullion cubes, and sugar• Liberal consumption of whatever fruits that is in season is encouraged o Pregnant women• Eat diet that contains a variety of foods in adequate amounts• Consume enough food to ensure adequate weight gain• Eat more of cereals, legumes, fruits, vegetables, dairy products, and animal foods• Take iron and folic acid supplements as prescribed• Avoid alcohol, addictive substances, and smoking o Breast-feeding mothers• Eat diet that contains a variety of available food items like cereals, tubers, legumes, meat, fish, milk, fruits, vegetables, etc.• Consume more of foods rich in iron such as liver, fi sh, beef, etc.• Eat fruits in season at every meal• Consume fluids as needed to quench thirst• Avoid alcohol, addictive substances and smoking o The elderly• Eat diets that are prepared from a variety of available foods for example cereals, tubers, fruits, vegetables, etc.• Increase consumption of fish and fish-based diets• Eat more of fruits and vegetables• Eat more frequently• Physical Activity/Exercise• Physical activity both as short periods of intense exercise or prolonged periods of modest activity on a daily basis generally has beneficial effects. 39
  42. 42. • Children and adolescents should engage in leisure time exercise • Adults should undertake some form of exercise as recommended by their doctors • Healthy Lifestyle • Some habits and lifestyles for example tobacco use and excessive alcohol consumption have been found to be bad for health • Prolonged indulgence in these lifestyles predisposes to noncommunicable diseases like cancer, diabetes, heart problems, and hypertension o Alcohol • Too much alcohol consumption can lead to risk of hypertension, liver damage, malnutrition, and various cancers. There is also the problem of alcohol abuse • If you must drink, take alcohol in moderation • Avoid drinking alcohol when driving a vehicle or operating any machinery o Tobacco • Tobacco use is associated with lung cancers and other chronic disorders. • Smoking during pregnancy can harm the developing baby and can result in low birth weight babies • Avoid the use of tobacco in any formOther available guidelines are; • Recommended Dietary Allowances, Estimated Safe And Adequate Daily Dietary Intakes, Daily Reference Intake, And Daily Values • American Cancer Society And National Cancer Institute Guidelines • World Health Organization Recommendations2.2 FOOD PYRAMIDThe food guide pyramid was introduced in 1992 by USDA (United States Department ofAgriculture) as a general plan of what to eat each day. The food guide pyramid is avaluable tool for planning a health promoting diet. 40
  43. 43. By incorporating the principle of balance, variety and moderation, an individual can stilleat their favorite foods while following the food guide pyramid.Balance: It means choosing food from different food groups. No single food can supplyall the nutrients needed to maintain good health. Similarly, not all foods in the samegroup contain the same nutrients. Oranges, for instance, do not contain much vitamin A,but cantaloupe is a good source of this vitamin. Choosing foods from all the food groupseach day and choosing avariety of foods within eachfood group will help youmeet your nutritionalrequirements. It will alsomake your diet moreinteresting.Variety: This meansincluding different foodswithin each food group. foreg. consuming a variety offruits.Moderation: This meanskeeping serving sizesreasonable. This involves self control.The food guide pyramid provides recommendation for the number of daily servings thatshould be consumed from each of the food groups.The diagram above clearly represents that cereals should form the major bulk of the dietfollowed by fruits and vegetables, pulses, milk and meat products and sugars and oil. Source: Srilakshmi .B 2003.Dietetics, New Age International (P) Publishers Ltd.ChennaiOther available guidelines are; • Recommended Dietary Allowances, Estimated Safe And Adequate Daily Dietary Intakes, Daily Reference Intake, And Daily Values 41
  44. 44. • American Cancer Society And National Cancer Institute Guidelines • World Health Organization Recommendations • others (Carolyn et al., 2007)2.3 EATING TIPS FOR A HEALTHY NUTRITIONEat a Variety of FoodsFoods contain combinations of nutrients and other healthful substances. No single foodcan supply all nutrients in the amounts you need. For example, oranges provide vitamin Cbut no vitamin B12; cheese provides vitamin B12 but no vitamin C. To make sure you getall of the nutrients and other substances needed for health, choose the recommendednumber of daily servings from each of the five major food groups: grains, vegetables,fruits, milk, meat and beans.Vegetarian Diets and Nutritional RequirementsSome Americans eat vegetarian diets for reasons of culture, belief, or health. Mostvegetarians eat milk products and eggs, and as a group, these lacto-ovo-vegetarians enjoyexcellent health. You can get enough protein from a vegetarian diet as long as the varietyand amounts of foods consumed are adequate. Meat, fish, and poultry are majorcontributors of iron, zinc, and B vitamins in most American diets, and vegetarians shouldpay special attention to getting these nutrients from vegetarian sources.Vegans eat only food of plant origin. Because animal products are the only sources ofvitamin B12, vegans must supplement their diets with a source of this vitamin. In addition,vegan diets, particularly those of children, require care to insure adequacy of vitamin Dand calcium, which most Americans obtain from milk products.Maintain a Healthy WeightIt is important for people of all ages to maintain a healthy weight. People who areoverweight increase their risk for high blood pressure, heart disease, diabetes, breathingproblems, and other illnesses. To maintain a healthy body weight, people must balance 42
  45. 45. the amount of calories in the foods and drinks they consume with the amount of caloriesthe body uses. Physical activity is an important way to use food energy. Extreme thinnessis also unhealthy. People who eat very little or diet excessively may not get the caloriesand other nutrients they need for good health.Aerobic exercise, such as walking, running, swimming, inline skating, and playingsoccer, burns fat and calories. Try to do 30 minutes or more of moderate physical activityon most—preferably all—days of the week.To Decrease Calorie Intake • Eat a variety of foods that are low in calories but high in nutrients—check the Nutrition Facts Label on the foods you eat. • Eat less fat and fewer high-fat foods. • Eat smaller portions and limit second helpings of foods high in fat and calories. • Eat more vegetables and fruits without fats and sugars added in preparation. • Eat pasta, rice, breads, and cereals without fats and sugars added in preparation. • Eat less sugar and fewer sweets like candy, cookies, cakes, and soda.Eat Plenty of Grains, Vegetables, and FruitsGrain products, vegetables, and fruits are key parts of a varied diet. They are emphasizedin this guideline because they provide vitamins, minerals, complex carbohydrates (starchand dietary fiber), and other substances that are important for good health. They are alsogenerally low in fat, depending on how they are prepared.FiberFiber is found only in plant foods like whole-grain breads and cereals, beans and peas,and other vegetables and fruits. Because there are different types of fiber in foods, choosea variety of foods daily. Eating a variety of fiber-containing plant foods is important forbowel function, can reduce symptoms of chronic constipation, and hemorrhoids, and maylower the risk for heart disease and some cancers.Choose a Diet Low in Fat, Saturated Fat, and Cholesterol 43
  46. 46. Some dietary fat is needed for good health. Fats supply energy and essential fatty acidsand promote absorption of the fat-soluble vitamins A, D, E, and K. More Americans arenow eating less fat, saturated fat, and cholesterol containing goods than in the recent past.Still, many people continue to eat high-fat diets. This guideline emphasizes the continuedimportance of choosing a diet with less total fat, saturated fat, and cholesterol.Avoid High-Fat FoodsSome foods and food groups are higher in fat than others. Fats and oils, and some typesof desserts and snack foods that contain fat provide calories but few other nutrients.Many foods in the milk group and in the meat and beans group (which includes eggs andnuts, as well as meat, poultry, and fish) are also high in fat, as are some processed foodsin the grain group.Fat, whether from plant or animal sources, contains more than twice the number ofcalories of an equal amount of carbohydrate or protein. Choose a diet that provides nomore than 30 percent of total calories from fat. The upper limit on the grams of fat inyour diet will depend on the calories you need. Cutting back on fat can help you consumefewer calories. For example, at 2,000 calories per day, the suggested upper limit ofcalories from fat is about 600 calories (65 grams of fat x 9 calories per gram = about 600calories).Maximum Total Fat Intake at Different Calorie Levels Calories 1,600 2,200 2,800 Total fat (grams) 53 73 93Saturated fat—Fats contain both saturated and unsaturated (monounsaturated andpolyunsaturated) fatty acids. Saturated fat raises blood cholesterol more than other formsof fat. Reducing saturated fat to less than 10 percent of calories will help you lower yourblood cholesterol level. The fats from meat, milk, and milk products are the main sourcesof saturated fats in most diets. Many bakery products are also sources of saturated fats.Vegetable oils supply smaller amounts of saturated fat.Monounsaturated and polyunsaturated fat—Olive and canola oils are particularlyhigh in monounsaturated fats; most other vegetable oils, nuts, and high-fat fish are good 44
  47. 47. sources of polyunsaturated fats. Both kinds of unsaturated fats reduce blood cholesterolwhen they replace saturated fats in the diet. Remember that the total fat in the diet shouldbe consumed at a moderate level—that is no more than 30 percent of calories.Monounsaturated and polyunsaturated fat sources should replace saturated fats within thislimit.Partially hydrogenated vegetable oils, such as those used in many margarines andshortenings, contain a particular form of unsaturated fat known as trans-fatty acids thatmay raise blood cholesterol levels, although not as much as saturated fat.Choose a Low Cholesterol DietThe body makes the cholesterol it requires. In addition, cholesterol is obtained from food.Dietary cholesterol comes from animal sources such as egg yolks, meat (especially organmeats such as liver), poultry, fish, and higher-fat milk products. Many of these foods arealso high in saturated fats. Choosing foods with less cholesterol and saturated fat willhelp lower your blood-pressure and blood-cholesterol levels.Avoid Too Much SugarSugars are simple carbohydrates. Dietary carbohydrates also include starch and fiber,which are complex carbohydrates. During digestion all carbohydrates except fiber breakdown into sugars. Sugars and starches occur naturally in many foods that supply othernutrients. Examples of these foods include milk, fruits, some vegetables, breads, cereals,beans, and grains. Some sugars are used as natural preservatives, thickeners, and bakingaids in food. The body cannot tell the difference between naturally occurring and addedsugars because they are identical chemically.Because maintaining a nutritious diet and a healthy weight is very important, sugarsshould be used in moderation by most healthy people and sparingly by people with low-calorie needs.Avoid Too Much SodiumSodium occurs naturally in foods, usually in small amounts. One form of sodium issodium chloride, commonly known as table salt. In the body, sodium plays an essentialrole in regulation of fluids and blood pressure. Most evidence suggests that many people 45
  48. 48. at risk for high blood pressure reduce their chances of developing this condition byconsuming less salt or sodium. Some questions remain, partly because other factors mayinteract with sodium to affect blood pressure.2.4 EFFECTS OF HEALTHY NUTRITION• Fuel to perform daily activities: A proper nutrition containing in the right proportions, proteins, fats and carbohydrates contribute to the total energy pool of the body which also uses vitamins and minerals to conserve and use the energy. These nutrients are also required for the production and maintenance of body tissues, electrical conduction of nerve activity, mechanical work of muscle effort and heat production to maintain body temperature. Diets deficient in these essentials lead to serious health problems.• Nutrients for the body cells: All systems e.g. cardiovascular, reproductive and respiratory systems can be broken down to cellular levels where hormones, enzymes and neurotransmitters are constantly interacting through complex processes to make the body function properly.• Growth and repair of tissues: During childhood and pregnancy, healing and the maintenance and buildup of muscle mass.• Reinforcing the immune system: Enables the body to fight diseases more effectively, thereby shortens the duration of illness and decrease the occurrence of illness.• Preventing chronic diseases of lifestyle: As tool for combating chronic disease of life style e.g. obesity and overweight that can lead to chronic diseases like diabetes type 2, heart diseases, hypertension, osteoarthritis and some cancer. This can be achieved by cutting down saturated fats and added sugars, include more plant -based foods in the diet as they have lower fat content, rich in fiber and also excellent sources of phytochemicals which are particularly used in prevention of cancer and heart 46
  49. 49. disease via its mechanism of neutralizing free radicals and thwarting enzymes that activate cancer causing agents in the body.• Maintaining good mental health: ‘’food is like a pharmaceutical compound that affects the brain’’ says Fernando Gomez-Pinilla (2008), The basic principle in preventing depression and mood swings, is to eat a balanced diet that contains foods from all different food groups- fruit and vegetables, unprocessed grains and cereals, lean meat, eggs, milk and dairy products, legumes and nuts, poly or monounsaturated margarine and oils, fatty fish e.g. tuna and salmon.• Ensuring healthy teeth and bones: A balanced calcium-rich diet especially during childhood, teen and early adulthood ensures adequate peak bone mass throughout life hence prevents osteoporosis in later life.(Kathleen et al, 2007)• Improve digestion, sleep and concentration, regular bowl, weight loss, improve skin tone and texture. 47
  50. 50. CHAPTER THREE3.0 UNHEALTHY NUTRITIONEach passing day, due to faulty eating habit various hazardous agents enter our bodythrough our diets, while neglecting the powerful foods and nutrients that can protect ourbody. Modern food industries use many preservatives, artificial colorants, additives andchemicals in order to enhance the appearance, flavor and shelf of food we eat. However,these compounds ultimately end up accumulating in our body only to show theirdeleterious effects in the form of diseases, cancers, and genetic malformations in thenew-born etc. (http://www.nutritionandyou.com).Poor nutrition especially mineral and vitamin deficiency, affects virtually the organs andgastrointestinal systems, organ functioning, and mental processes are diminished,influences the production of central nervous system, neurotransmitters, and whenneurotransmitters like dopamine, serotonin are diminished, there is a resultant mood inbalance and both a decreased ability to resist temptation and a greater perceived need fora pleasurable effects of intoxication (Nutrition in drug rehabilitation, 2010). Unhealthydieting is a major risk factor for a number of chronic or western diseases including highblood pressure, diabetes, abnormal blood lipids, overweight or obesity, cardiovasculardiseases and cancer (WHO, 2007). The WHO (2007) estimates that 2.7 million deaths areattributed to a diet low in fruit and vegetable every year. Globally, it is estimated to causeabout 19% of gastrointestinal cancer, 31% ischaemic heart disease, and 11% strokes(WHO, 2007). 48
  51. 51. Poor nutrition can also impair neural development, leading to lower intelligence quotientin humans and flawed song learning in birds. Scientific research has also gathered thatpoor nutrition early-on in a child’s life brings about social problems. The child developsan anti-social and aggressive behavior which he will have to live with till the end of hisadolescent years (Carey, 2005).3.1 MALNUTRITIONMalnutrition as defined by World Health Organisation (WHO) is a pathological stateresulting from a relative or absolute deficiency or excess of one or more essentialnutrients, this state being clinically manifested or detected only by biochemical,anthropometric or physiological tests.Four forms can be distinguished:a. Under nutrition – the pathological state resulting from the consumption of aninadequate quantity of food over an extended period of time.b. Marasmus is synonymous with severe under nutrition. Starvation implies totalelimination of food and hence the rapid development of under nutrition and marasmus.c. Specific deficiency – the pathological state resulting from a relative or absolute lack ofan individual nutrient.d. Over nutrition – the pathological state resulting from a disproportion of essentialnutrients with or without the absolute deficiency of any nutrient as determined by therequirement of a balanced diet.Need for and Methods of Assessing Nutritional StatusNutritional status is the condition of health of the individual as influenced by theutilization of the nutrients. It can be determined by correlation of information obtainedthrough medical and dietary history, thorough physical examination and laboratoryinvestigation.Nutritional assessment aids in identifyinga) Under Nutrition 49
  52. 52. b) Over Nutritionc) Nutritional deficienciesd) Individuals at the risk of developing malnutritione) Individuals at the risk of developing nutritional related diseasesf) The resources available to assist them to overcome nutritional problems.3.2 EATING DISORDERSEating disorders occur over a continuum of increasingly pathological behavior. Excessiveself-evaluation and a preoccupation with weight, shape, and size characterize bothAnorexia Nervosa (AN) and Bulimia Nervosa (BN). Other common characteristicsinclude an intense fear of weight gain and a relationship with food that borders onobsessive. However, there are distinct differences between the two disorders (Christian,2007).Anorexia NervosaAlthough AN often starts with only small reductions in total food intake, patientseventually reduce their energy and fat intake to a point where they are consuming only alimited number or foods in a highly ritualistic fashion. Although patients often suggestthat they cannot eat or that they are not hungry, an actual loss of appetite is quite rare.Individuals with AN refuse to maintain a minimally normal and healthy body weight,show an intense fear of gaining weight or becoming fat, exhibit a disturbance in theirperception of their body weight or shape, and experience abnormal menses.Implications• The disorder is characterized by severe, voluntary starvation (300 - 600 kcal per day).• Refusal to maintain body weight at or above 85% of expected for height and age (could include a BMI ≤ 17.5)• Body image disturbances, which may include the denial or lack of appreciation for the seriousness of one’s currently low weight,• In females, primary or secondary amenorrhea 50
  53. 53. Bulimia NervosaCharacterized by recurrent episodes of eating unusually large quantities of food at a meal,and eating until the food is gone or the person is uncomfortably or painfully full. Effortsto purge the excess food, typically between 1000 to 2000 kcal by some compensatory orpurging behavior such as vomiting, laxative or diuretic abuse, excessive exercise, andrestrictive dieting or fasting occur subsequent to the binge-eating episode. Some patientsmay binge and purge over an extended period of time, consuming close to 10,000 kcal.Amphetamine use may also occur in an attempt to restrict one’s appetite. These behaviorsare associated with a sense of loss of control and typically, shame, guilt, andembarrassment are associated with the binge-eating and purging process. Nevertheless,patients often report that the purging behaviors diminish the intensity of aversiveemotions and provide them with a sense control. Similar to the diagnosis of AN, patientsare further classified as either of two subtypes. Worthy of note is the fact that 25 to 30%of patients with BN have a prior history of AN (Christian, 2007).Implications • Recurrent episodes (a minimum average of twice per week for at least 3 months) of binge eating, defined as eating an abnormally large amount of food. • Within a 2-h period, they are associated with a sense of lack of control over the eating process during the episode. • Use of compensatory or purging behavior such as self-induced vomiting, laxative/enema or diuretic abuse, restrictive dieting, fasting, or excessive exercise. • Self-evaluation largely determined by one’s shape and weight.Binge-Eating DisorderThis disorder is more nebulous, and is characterized by recurrent binge-eating episodeswithout a compensatory effort to eliminate caloric excess. It has only been widelyrecognized over the past 10 to 15 years. In fact, a diagnostic criterion for BED is not yetapproved. Although persons diagnosed with BED are seen with a wide range of weights,most are obese. Although the age of onset is the same for BED, these patients typically 51
  54. 54. do not present for treatment until they are much older and already overweight or obese(Christian, 2007).Implications • Eating much more rapidly than usual • Eating until uncomfortably full • Eating large amounts of food despite not feeling physically hungry • Eating alone because of embarrassment over quantity of food consumed • Feeling disgusted, depressed, guilty, or ashamed after the binge3.3 SELECTED FOOD RELATED DISEASE CONDITIONS3.3.1 ObesityThe role of nutrient intake in promoting obesity is quantitative, qualitative, and temporal.The increasing availability of food, often in excessive serving sizes, promoteshyperphagia. Hedonic factors such as food texture, temperature, color, appearance, andvariety may also lead to overconsumption. Visual cues also influence intake; subjectseating from covertly self-refilling bowls consumed 73% more than subjects eating fromnormal bowls. Carbohydrates with a high glycemic response may promote obesity byaltering fuel partitioning, that is, promoting postprandial carbohydrate oxidation andsparing fat oxidation. A dramatic increase in high-fructose corn syrup temporallycorrelates with the development of the obesity epidemic. Compared to glucose,differences in the metabolism of fructose may promote adiposity.The intake of dietary fat is significantly related to adiposity. Dietary fat is converted tobody fat with approximately 25% greater efficiency than carbohydrate. Dietary fat maybe less satiating than protein and complex carbohydrates, although foods with a highglycemic index (i.e., rapidly converted to glucose) may stimulate hunger and lead to morefrequent eating. The long-chain fatty acid composition of dietary fat influences energyutilization; low ratios of polyunsaturated to saturated fat are associated with lowerrespiratory quotients (RQ; moles of carbon dioxide produced per mole of oxygenconsumed). The pattern of food intake may play a role in the development of obesity.Widely spaced meals are used less efficiently because of the energy cost of storage. 52
  55. 55. Compared to immediate oxidation, the energy cost of converting glucose into glycogen is5%, and into fat is 28%. Body Mass IndexThe BMI is highly correlated with fatness, and minimizes the effect of height. It iscalculated as:BMI = wt (in kg)/ht2 (in meters) or BMI = wt (in lb) × 703/ht2 (in inches)As an index of mass, it does not distinguish between fat and fat-free mass. Consequently,it is possible to be overweight without having excess adiposity (very muscularindividuals) as well as obese without being overweight (sarcopenic individuals).classification for BMI.BMI Weight Classification18.5–24.9 Normal weight25.0–29.9 Overweight30.0–34.9 Class 1 obesity35.0–39.9 Class 2 obesity>40 Class 3 obesity3.3.2 HypertensionDietary sodium plays an important role in the determination of blood pressure, andreductions in sodium intake by 1.8 g/day have been associated with reductions in systolicand diastolic blood pressure of approximately 4 and 2 mmHg, respectively. The DietaryApproaches to Stop Hypertension (DASH) diet, a carbohydrate-rich diet that emphasizedfruits, vegetables, and low-fat dairy products and reduced saturated fat, total fat, anddietary cholesterol, showed significant effects on reducing hypertension at all levels ofsalt intake. More recently, in the follow-up study entitled the OMNI-HEART study,replacement of carbohydrate with protein or unsaturated fat led to even greater decreasesin blood pressure in prehypertensive and stage 1 hypertensive participants. A reduction inLDL and HDL cholesterol was seen when carbohydrate was replaced with protein but notwith unsaturated fat. 53
  56. 56. In the CARDIA study, 4304 young adults were followed for over 15 years in amulticenter, population-based, prospective study of CVD risk evolution. Diets rich inwhole grains, refined grains, fruits, vegetables, nuts, or legumes were found to beinversely related to blood pressure, while positive effects of red and processed meatintake on blood pressure were observed.In an epidemiologic study of approximately 1700 persons, those consuming 14 or moreservings of fruit or vegetables per day were likely to have less of an increase in bloodpressure than persons consuming less than 14 servings per day of fruits and vegetablesafter a 7-year follow-up.3.3.3 HyperinsulinismInsulin is the hormone - produced by the pancreas - that allows glucose into cells where itcan be utilized as fuel. Through bad luck (heredity) and lifestyle (too much dietarycarbohydrate chiefly) your cells can become resistant to insulin. The mechanism of thisresistance is still being studied but we know that the insulin receptors that sit on everycell’s surface lose their ability to function. This causes the pancreas to secrete moreinsulin than is normal to get glucose inside the cell. Though insulin is absolutely essentialto life, chronic and acute elevation of insulin wreaks havoc in the human body. Thisprocess is known as “insulin resistance” and the resultant condition is“hyperinsulinemia”.The amount of research being published suggesting a causal link betweenhyperinsulinism and disease is one of the more productive and exciting arenas in modernmedicine. There is mounting evidence linking hyperinsulinemia to:Hypercholseterolemia, Hypertriglyceridemia, Obesity, Hypertension, Immune disorders,Thrombosis and platelet aggregation, Cellular proliferation, Diabetes, Heart disease,Mood dysfunction, Brain dysfunction, Arthritis, Hyper inflammatory states, Alzheimer’sdisease, Stroke, Osteoporosis, Metastasis, Angiogenesis and Cancer3.3.4 Alcoholism 54
  57. 57. Alcoholic beverages have been consumed by humans since the dawn of history. Theyhave been used to ease anxiety, to promote social interaction, and as a vehicle todominate others. Ethanol, a two-carbon alcohol in beverages such as beer, wine, whiskey,gin, and other liquors, is the quantitative end product of yeast glycolysis. Small amountscan be synthesized in mammalian cells. Ethanol has an energy value of 7.1 kcal/g. Thus,ethanol is a psychoactive drug, an energy-rich dietary ingredient, and a metabolite.It has been estimated that upward of 90 million Americans consume alcoholic beveragesevery day and that about 18 million people are addicted to its consumption.Alcoholism is more prevalent in certain cultural groups than in others. For example,alcoholism is quite prevalent in Native American population groups. Alcoholism hasprofound effects on nutrient need as well as nutritional status. Chronic alcohol use ofgreater than 80 g/day for more than 10 years increases the risk of hepatocellularcarcinoma approximately five fold. 1 Excess alcohol consumption is associated withcirrhosis and also with an increase in risk for hepatitis C.2–6 People who are addicted toits consumption are at nutritional risk as well. The mechanisms by which these conditionsdevelop are incompletely understood but may include damage to plasma membranes,damage to nuclear DNA, oxidative stress, destruction of retinoic acid, and altered DNAmethylation (www.themedicalbiochemistrypage.com). MetabolismEthanol, once consumed, is rapidly absorbed by simple diffusion. The diffusion isaffected by the amount of alcohol consumed, the regional blood flow, the surface area,and the presence of other foods. The different segments of the gastrointestinal tractabsorb ethanol at different rates. Absorption is fastest in the duodenum and jejunum,slower in the stomach, ileum, and colon, and slowest in the mouth and esophagus. Therate of absorption by the duodenum depends on gastric emptying time, which, in turn,depends on the kinds and amounts of foods consumed with the ethanol. Certain drugsmay also influence gastric emptying time and thus influence absorption. Completeabsorption may vary from 2 to 6 h. The type of beverage can influence ethanol 55

×