2. INTRODUCTION
Food is that which nourishes the body. Food may also be defined as anything eaten or
drunk, which meets the needs for energy, building, regulation and protection of the body.
Nutrition is the process of providing or obtaining the food necessary for health and growth.
Nutrition includes everything that happens to food from the time it is eaten until it is used for
various functions in the body.
Nutrients are components of food that are needed by the body in adequate amounts in order
to grow, reproduce and lead a normal, healthy life.
Nutrients include water, proteins, fats, carbohydrates, minerals and vitamins.
They are used to produce literally thousands of substances necessary for life and physical
fitness.
3.
4. Adequate, optimum and good nutrition are expressions used to indicate that the supply of the
essential nutrients is correct in amount and proportion.
Nutritional status is the state of our body as a result of the foods consumed and their use by the
body. Nutritional status can be good, fair or poor.
The characteristics of GOOD NUTRITIONAL STATUS
1. A well developed body, with normal weight for height ( BODY MASS INDEX / BMI – Kg / m²)
2. Well developed and firm muscles
3. Healthy skin, reddish pink colour of eyelids
4. Membranes of mouth healthy, good layer of subcutaneous fat,
5. Clear eyes, smooth and glossy hair,
6. Good appetite and excellent general health ( stamina for work, regular meal times, sound
regular sleep, normal elimination and resistance to disease )
5. The characteristics of POOR NUTRITIONAL STATUS is evidenced by
1. undersized poorly developed body, abnormal body weight (too thin or fat and flabby body),
2. muscles small and flabby,
3. pale or sallow skin,
4. too little or too much subcutaneous fat,
5. dull or reddened eyes, lusterless and rough hair,
6. poor appetite, lack of vigor and endurance for work and susceptibility to infections.
Poor nutritional status may be the result of poor food selection, irregularity in schedule of
meals, work, sleep and elimination.
6. The WHO (World Health Organization) has defined health as the ‘state of complete physical, mental
and social well-being and not merely the absence of disease or infirmity’.
Malnutrition means an undesirable kind of nutrition leading to ill-health. It results from a lack, excess
or imbalance of nutrients in the diet. It includes
1. Under nutrition is a state of an insufficient supply of essential nutrients. Malnutrition can be
primarily be due to insufficient supply of one or more essential nutrients; or it can be secondary,
which means it results from an error in metabolism, interaction between nutrients or nutrients
and drugs used in treatment.
2. Over nutrition refers to an excessive intake of one or more nutrients, which creates a stress in
the bodily function.
Diet refers to whatever you eat and drink each day. Thus it includes the normal diet you consume
Diet may also be modified and used for ill persons as part of their therapy (therapeutic diets).
7. FUNCTIONS OF FOOD
PHYSIOLOGICAL FUNCTIONS OF
FOOD.
1. provide energy. The body to convert
food ingested into usable nutrients in
the body, to grow and to keep warm.
2. building the body. The food eaten
each day helps to maintain the structure
of the adult body, and to replace worn
out cells of the body.
3. regulate activities of the body.
• Beating of the heart
• Maintenance of the body
temperature
• Muscle contraction
• Control of water balance
• Clotting of blood
• Removal of waste products from
the body
4. resistance to disease.
11. Carbohydrates are macronutrients, meaning they are one of the three main ways the
body obtains energy, or calories
Carbohydrates are the sugars, starches and fibers found in fruits, grains, vegetables
and milk products.
The recommended daily amount (RDA) of carbs for adults is 135 grams, according to
the National Institutes of Health (NIH.
Carb intake for most people should be between 45% and 65% of total calories. One
gram of carbohydrates equals about 4 calories.
People with diabetes should not eat more than 200 grams of carbs per day, while
pregnant women need at least 175 grams.
INTRODUCTION
12. GOOD CARBOHYDRATES ARE:
Low or moderate in calories
High in nutrients
Devoid of refined sugars and refined grains
High in naturally occurring fiber
Low in sodium
Low in saturated fat
Very low in, or devoid of, cholesterol and trans fats
13. BAD CARBOHYDRATES ARE:
High in calories
Full of refined sugars, like corn syrup, white sugar, honey and fruit juices
High in refined grains like white flour
Low in many nutrients
Low in fiber
High in sodium
Sometimes high in saturated fat
Sometimes high in cholesterol and trans fats
14.
15.
16. FUNCTIONS
1. The primary function of carbohydrates in the body is to supply energy. Each gram of
carbohydrate, as starch or sugar, provides 4 kcal/g. The brain and the central nervous
system are dependent on the constant supply of glucose from the blood to meet their
energy needs.
2. Carbohydrates act also as reserve fuel supply in the form of glycogen, stored in
muscles and liver. The total amount of glycogen in the body is over 300g. But it must be
maintained by regular intake of carbohydrates at frequent intervals, so that the
breakdown of fat and protein tissue is prevented.
3. Carbohydrates serve other special functions in the body. Carbohydrates provide
chemical framework, which combine with the nitrogen to synthesise non-essential
amino acids in the body.
17. 4. Carbohydrates and their derivatives work as precursors of important metabolic
compounds. These include nucleic acids, the matrix connective tissue and
galactosides of nerve tissue.
5. Lactose, the milk sugar, provides galactose needed for brain development. It aids
absorption of calcium and phosphorus, thus helping bone growth and maintenance.
6. Lactose forms lactic acid in the intestinal track due to the action of the bacteria
(lactobacilli) present there. These lactobacilli synthesise some of the B-complex
vitamins. It aids, bacteria(lactobacilli) present to suppress the activities of
putrefactive bacteria and protects us fromtheir undesirable effects.
18. 7. Carbohydrates are an important part of some compounds, which increase our resistance to
infection (immunopolysaccharides). Ribose, a five carbon sugar, is an essential part of DNA
and RNA. Carbohydrates are a part of important compounds, which are components of
nervous tissue (galactolipid), heart valve, cartilage, bone and skin (chondroitin sulfate).
8. Carbohydrates are needed for ensuring complete normal metabolism of fats, thus
preventing acidosis.
9. Carbohydrates are needed to prevent dehydration. A low carbohydrate diet causes loss of
water from tissues as also electrolytes (especially sodium and potassium) in the urine and can
lead to involuntary dehydration.
10. Dietary fibre acts like a sponge and absorbs water. It helps smooth movement of food
waste through the digestive tract and the soft, bulky stools are comfortably eliminated.
19. Food Sources
Carbohydrates are synthesised by plants and occur in several forms.
Starch is found in plant seeds (cereals and legumes), roots and tubers. These foods are the
primary energy sources in the human dietary.
Potatoes, yams, jackfruit are good source of starch in the diet.
Vegetables and fruits provide dietary fiber, minerals and vitamins.
Milk is the only animal food, which is the source of a very important sugar lactose in the diet.
20. Sugars are found in fruits. Fruits are an excellent snack food as they are a
dilute source of quick energy and other nutrients.
Sugars found in plant sap or juice (sugarcane and beetroot) is extracted to give
pure 100 per cent sugar. It must be used judiciously, as it provides only energy.
The intake of foods high in added sugars, such as soft drinks, syrups and
sweets needs to be controlled to avoid obesity.
24. Proteins are very large organic compounds.
Proteins, like carbohydrates and fats, contain carbon, hydrogen and oxygen.
In addition, proteins contain about 16 per cent nitrogen, which is their unique
feature and distinguishes them from carbohydrates and fats.
Some proteins also contain sulphur and sometimes phosphorus, iron and cobalt.
Proteins are more complex than fats and carbohydrates, as the size of the
molecule is large and there is a great variation in the units from which it is
formed.
INTRODUCTION
25. Next to water, protein is the most abundant component of the body.
It accounts for about a sixth of the live body weight
a third of it is found in the muscles,
a fifth in the bones and cartilage,
a tenth in the skin
the remainder in other tissues and body fluids.
There are thousands of different specific proteins in the body, each having a unique
structure and function. For this reason, the word protein implies not one but a large
group of complex compounds.
Proteins are present in all living tissues, both plant and animal. They are essential to life
because vital parts of the nucleus and protoplasts of every cell are proteins.
26. Plants are the primary source of proteins in nature.
Proteins are synthesised by the plants from the nitrates and ammonia in
the soil. Herbivorous animals use plant proteins to meet their protein
needs.
Humans uses plant foods as also animal foods (milk and meat) to meet
their protein needs.
Nitrogen is returned to the soil through degradation of products of animal
metabolism, excretion of nitrogen compounds in urine and faeces, and
decomposition of animal body at death, to complete the natural nitrogen
cycle.
27. STRUCTURE OF PROTEIN
All proteins in our body and food are built from basic units or compounds known as amino
acids.
Amino acids combine to form proteins by means of a peptide bond
Polypeptiddes thus formed constitute the primary structure of proteins.
The secondary structure formed by linking several polypeptide chains may be helical, pleated
or random coil.
More complex proteins have a tertiary structure in whcih the polypeptide chain is wound into
a globular form.
28.
29. Proteins exist in fibrous or globular form.
Fibrous proteins appear in structure elements, e.g., collagen of connective tissue,
myosin of muscle tissue and keration of hair.
Globular proteins are very soluble and occur in tissue fluids; these include casein, egg
albumin, albumins and globulins of blood plasma and haemoglobin.
In conjugated form, they form most of the intracellular enzymes.
30.
31. Simple proteins yield only amino acids on hydrolysis. Albumins, globulins, glutelins, prolamins
and albuminoids are simple proteins.
Conjugated proteins are combinations of simple proteins with non-protein substances. The
combinations result in formations, which are functionally very important to the body.
Conjugated proteins include:
• Lipoproteins (proteins + lipids) found in blood plasma (HDL, LDL, VLDL, etc.).
• Nucleoproteins (proteins + nucleic acids) found in cells (RNA, DNA).
•Mucoproteins and glycoproteins (proteins + polysaccharides) found in gastric secretion (mucin).
• Phosphoproteins (proteins + phosphoric acid) are found in milk, e.g., casein.
• Metalloproteins (proteins + metals) are found in ferritin, hemosidirin.
Derived proteins are proteoses, peptones and peptides formed in the various stages of protein
metabolism.
32. Functions
The primary function of proteins is tissue building.
Proteins are the main solid matter in the muscles, they are also the major
constituents of blood,
matrix of bones, teeth, skin, nails and hair. Our body, which consists of about 60 per
cent water and 19 per cent fat is held together by only 17 per cent proteins and 4 per
per cent minerals.
33. The principal functions of proteins in the body are discussed below.
Body-Building or Building of New Tissues:
Maintenance of tissues
Regulatory Functions:
Proteins as Precursors of Enzymes, Hormones and Antibodies:
Transport of Nutrients
Milk Formation
Energy Supply
34.
35. Deficiencies
Children tend to have retarded growth but this may not be noticed
Protein deficiency during pregnancy may result in stress,
Severe Deficiency: If there is severe deficiency of protein in the first two years of life, it
could affect mental development, learning ability and behaviour.
In India and other tropical developing countries, protein-energy malnutrition (PEM) is a
common disorder during childhood. When the child is weaned, the diet often does not
contain an adequate quantity and quality of protein which results in deficiency diseases.
36. When an infant is fed high carbohydrate low protein foods such as ragi (corn starch
porridge), kwashiorkor, a typical protein deficiency condition occurs.
When both protein and calorie are very low in the diet, nutritional marasmus could
occur. In other words, kwashiorkor is a deficiency disease due to severe lack of protein
but nutritional marasmus is due to sheer starvation.
The education of prospective parents about childcare and nutrition can ensure good
nutrition of infants and young children and prevent protein-calorie malnutrition. Greater
attention is needed to appropriate supplementary nutrition for children in the 0–2 age
group, the most critical period in terms of brain and body growth.
38. VITAMINS
Organic in nature
Required in minimal quantities for proper growth and regulatory functions
Improper intake leads to a varied no of deficiencies
39. MINERALS
Present in small quantities to regulate metabolic functions
4 % of body weight
Microelements - only needed and present in trace quantities
Zinc, Boron, Manganese, Silicon, Arsenic ……
Macroelements - minerals needed greater than 1 gram in our body
Calcium, Magnesium, Potassium, Phosphorous, Sulphur, Chloride and Iron.
40. Nutrient Function
Deficiency
Symptoms
Major Food
Sources
Vitamin A
Preserves integrity of epithelial
cells; formation of rhodopsin
for vision in dim light;
necessary for wound healing,
growth, and normal immune
function
Night blindness, dry eyes, poor
bone growth, impaired
resistance to infection, papillary
hyperkeratosis of the skin
Breast milk, infant formula,
liver, egg yolk, dark green
and deep yellow vegetables
and fruits
Vitamin D
Necessary for the formation
of normal bone; promotes the
absorption ofcalciumand
phosphorus in the intestines
Rickets (symptoms: epiphyseal
enlargement, cranial bossing,
bowed legs, persistently open
anterior fontanelle)
Infant formula, egg yolk, liver,
fatty fish, sunlight (activation
of 7-dehydrocholesterol in
the skin)
Vitamin E
May function asan antioxidant
in the tissues; may also have a
role asa coenzyme; neuromus-
cular function
Hemolytic anemia in the
premature and newborn;
hyporeflexia, and
spinocerebellar and retinal
degeneration
Breast milk; infant formula;
vegetable oils; liver; egg yolk;
butter; green leafy
vegetables; whole-grain
breads, cereals, and other
fortified or enriched grain
products; wheat germ
41. NUTRIENT FUNCTION
DEFICIENCY
SYMPTOMS
MAJOR FOOD
SOURCES
Vitamin K
Catalyzes prothrombin
synthesis; required in the
synthesis of other blood clotting
factors; synthesis by intestinal
bacteria
Prolonged bleeding and
prothrombin time;
hemorrhagic manifesta-
tions (especially in
newborns)
Infant formula, vegetable
oils, green leafy
vegetables, pork, liver
Thiamin
(Vitamin B1)
Combines with phosphorus to
form thiamin pyrophosphate
(TPP) necessary for metabolism
of pro- tein, carbohydrate, and
fat; essen- tialforgrowth, normal
appetite, digestion, and healthy
nerves
Beriberi, neuritis, edema,
cardiac failure
Breast milk; infant formula;
lean pork; wheat germ;
whole-grain and enriched
breads, cere-
als, and other grain
products; legumes;
potatoes
Riboflavin
(Vitamin B2)
Essential for growth; plays
enzymatic role in tissue respira-
tion and acts as a transporter of
hydrogen ions; synthesis of FMN
and FAD
Photophobia, cheilosis,
glossi- tis, corneal
vascularization, poor
growth
Breast milk; infant
formula, meat; dairy
products; egg yolk;
legumes; green
vegetables; whole-grain
breads, cereals, and
fortified or enriched grain
products
42. Nutrient
Functio
n
Deficiency
Symptoms
Major Food Sources
Niacin
(Vitamin B3)
Part oftheenzyme system
for oxidation, energy
release; nec- essaryfor
synthesisofglycogen and
the synthesis and break-
down of fatty acids
Pellegra: dermatitis, diarrhea,
dementia
Breast milk; infant formula; meat;
poultry; fish; whole-grain breads,
cereals, and fortifiedor enriched grain
products; egg yolk
Pantothenic Acid
(Vitamin B5)
Functionsinthesynthesis
and breakdownofmanyvital
body compounds; essential
in the intermediary
metabolism of
carbohydrate,fat,and
protein
Fatigue; sleep disturbances;
nausea; muscle cramps;
impaired coordination; loss of
antibody production
Breast milk; infant formula; meat; fish;
poultry; liver; egg yolk; yeast; whole-
grain breads, cereals, and other grain
prod- ucts; legumes; vegetables
43. Nutrient Function Deficiency Symptoms Major Food Sources
Pyridoxine
(Vitamin B6)
Aidsinthesynthesisandbreak- down
ofaminoacidsandunsaturatedfatty
acidsfromessential fattyacids;
essentialforconversionoftryptophanto
niacin;es- sential for normal growth
Microcytic anemia;
convulsions; irritability
Breast milk; infant formula; liver;
meat;whole-grainbreads, cereals,or
othergrainproducts; legumes;
potatoes
Folacin
(Vitamin B9)
Essentialinthebiosynthesisof nucleic
acids; necessary for the normal
maturation of red blood cells
Poor growth; megaloblastic ane- mia
(concurrentdeficiencyofvi- taminB12
shouldbesuspected); impairedcellular
immunity
Breast milk; infant formula; liver;
green leafy vegetables; legumes;
whole-grain breads, cereals, and
fortified or en- riched grain products;
legumes; oranges; cantaloupe; lean
beef
Vitamin B12
(Cobalamin,
Cyanocobala
min)
Essential for biosynthesis of nucleic
acidsandnucleoproteins; redbloodcell
maturation;involved with folate
metabolism; central nervous system
metabolism
Pernicious anemia; neurologic
deterioration
Infantformula,breastmilk, meat,
fish,poultry,cheese, egg yolk,
liver
44. Nutrient Function
Deficiency
Symptoms
Major Food Sources
Biotin
Essential component of en- zymes;importantin
reactions involvingthelengtheningofcar- bon chains;
coenzyme carrier of carbondioxide;plays an impor-
tantroleinthemetabolismof fatty acids andamino
acids
Seborrheic dermatitis; glossitis;
nausea; insomnia;
Breastmilk,infantformula,liver, meat,
eggyolk,yeast,bananas, most
vegetables, strawberries, grapefruit,
watermelon,
Ascorbic
Acid
(Vitamin C)
Essentialinthesynthesisofcol- lagen(thus,
strengthenstissues and improves wound healing
and resistance to infection);iron absorption and
transport;water- soluble antioxidant; functions in
folacin metabolism
Scurvy,pinpointperipheralhemor-
rhages, bleeding gums, osmotic
diarrhea
45. Nutrient Function
Deficiency
Symptoms
Major Food Sources
Calcium
Buildsandmaintainsbonesand teeth; essential
in clotting of blood; influences transmission of
ionsacrosscellmembranes; requiredinnerve
transmission
Rickets –abnormal develop- ment
of bones.
Breast milk, infant formula, yogurt, cheese,
fortified or enrichedgrainproducts,some
greenleafyvegetables(suchas collards,
kalemustardgreens, and turnip greens),
tofu (if made with calcium sulfate),
sardines, salmon
Iodine
Helps regulate thyroid hor- mones; important
in regulation ofcellularoxidationandgrowth
Endemic goiter; depressed thy- roid
function; cretinism
Breastmilk,infantformula, seafood,
iodizedsalt
Iron
Essentialfortheformationof hemoglobin and
oxygen trans- port;increasesresistanceto
infection;functionsaspart
ofenzymesinvolvedintissue respiration.
Hypochromic microcytic ane- mia;
malabsorption; irritability; anorexia;
pallor, lethargy
Breast milk; infant formula; meat; liver;
legumes; whole- grainbreads,cereals,or
fortifiedorenrichedgrainproducts; and dark
green vegetables
Potassium
Helpsregulateacid-baseequi- libriumand
osmoticpressureof bodyfluids;influences
muscle activity, especially cardiac muscle
Muscle weakness; decreased
intestinal tone and distension; cardiac
arrhythmias; respiratory failure
Breastmilk;infantformula; fruitsespecially
orangejuice, bananas, and dried fruits;
yogurt;potatoes;meat;fish; poultry; soy
products; vegetables
46. Nutrient Function Deficiency Symptoms Major Food Sources
Phosphorus
Builds andmaintainsbonesand teeth; component
ofnucleicac- ids, phospholipids; ascoenzyme
functions in energy metabolism; buffers
intracellularfluid
Phosphate depletion unusual
– effects renal, neuromuscular,
skeletal systems as well as blood
chemistries
Breast milk; infant formula; cheese;
eggyolk;meat;poultry; fish; whole-
grain breads, cereals,andothergrain
products; legumes
Sodium
Helps regulate acid-base equi- librium and
osmotic pressure of body fluids; plays a role in
normal muscle irritability and contractility;
influences cell permeability
Nausea; cramps; vomiting;
dizziness; apathy; exhaustion;
possible respiratory failure
Sodium chloride (table salt),
abundantinmostfoodsexcept fruit
Chloride
Helps regulate acid-base equi- librium and
osmotic pressure of body fluids; component of
gastric juices
Usually accompanied by sodium
depletion; see Sodium
Breastmilk,infantformula, sodium
chloride (table salt)
Magnesium
Required for many coenzyme oxidation-
phosphorylation reac- tions, nerve impulse
transmis- sions, and for muscle contrac- tion
Muscle tremors; convulsions;
irritability; tetany; hyper-or
hypoflexia
Breast milk; infant formula; whole-
grainbreads,cereals, andother
grainproducts;tofu; legumes;green
vegetables
48. INTRODUCTION
Fats are one of the three main macronutrients, along with carbohydrates and proteins.
Fat molecules consist of primarily carbon and hydrogen atoms.
They are hydrophobic and are soluble in organic solvents and insoluble in water.
Examples include cholesterol, phospholipids, and triglycerides.
Fats serve both structural and metabolic functions.
Important form of fat needed by our body is omega - 3 – fatty acids and linolenic acid.
49. GOOD FATS
Doctors consider monounsaturated fat and polyunsaturated fat more “heart-healthy” fats.
Foods that primarily contain these healthier fats tend to be liquid when they’re at room
temperature. An example is vegetable oil.
Monounsaturated fat can improve your blood cholesterol level and decrease your risk of
cardiovascular disease. These foods include:
nuts (almonds, cashews, peanuts, pecans)
vegetable oils (olive oil, peanut oil)
peanut butter and almond butter and avocado
50. Omega-3 decrease the risk of coronary artery disease, but also help lower blood pressure levels
and guard against irregular heartbeats.
The following types of fatty fish contain omega-3 fatty acids:
salmon
herring
sardines
trout
You can also find omega-3s in flaxseed, walnuts, and canola oil, although these contain a less
active form of the fat than fish do.
51. Bad fats
Two types of fats — saturated fat and trans fat — have been identified as potentially harmful to
your health.
Most of the foods that contain these types of fats are solid at room temperature, such as:
butter
margarine
shortening
beef or pork fat
Trans fat should be avoided while saturated fats should be eaten very sparingly.
52. Types of fats
Fatty acid chains may also differ by length, often categorized as short to very long.
Short-chain fatty acids (SCFA) are fatty acids with aliphatic tails of fewer than six carbons (i.e.
butyric acid).
Medium-chain fatty acids (MCFA) are fatty acids with aliphatic tails of 6–12 carbons, which can
form medium-chain triglycerides.
Long-chain fatty acids (LCFA) are fatty acids with aliphatic tails of 13 to 21 carbons.
Very long chain fatty acids (VLCFA) are fatty acids with aliphatic tails of 22 or more carbons.
53. Importance
Fats are also sources of essential fatty acids, an important dietary requirement.
They provide energy.
Vitamins A, D, E , and K are fat-soluble, meaning they can only be digested, absorbed, and transported in conjunction with
fats.
Fats play a vital role in maintaining healthy skin and hair,
insulating body organs against shock, maintaining body temperature, and promoting healthy cell function.
When a particular substance, whether chemical or biotic, reaches unsafe levels in the bloodstream, the body can effectively
dilute or at least maintain equilibrium of the offending substances by storing it in new fat tissue. This helps to protect vital
organs, until such time as the offending substances can be metabolized or removed from the body by such means
as excretion, urination, accidental or intentional bloodletting, sebum excretion, and hair growth.
54. Related health problems
Fat Hurts Your Heart
Every major system in your body feels the stress of excess weight. The heart is the
most obvious victim -- as cholesterol builds, blood pressure rises, and arteries get
clogged. Also, the blood loses its ability to clot which increases stroke risk.
Fat Ups Male Hormones
Overweight women have higher levels of male hormones, which ups their risk of heart
disease. Those hormones also cause male pattern balding, some excess facial hair,
and acne.
Fat Triggers Diabetes
Excess weight affects another hormone -- insulin -- which leads to diabetes. Having
diabetes increases your heart disease risk.
55. Fat Ruins Sleep
Overweight people often suffer from sleep disorders. The most dangerous is sleep
apnea. With sleep apnea, you stop breathing many times during the night. This makes
your oxygen level drops-- which affects the heart, blood vessels, stroke risk, and
diabetes risk.
Fat Wrecks Hips, Knees
The sheer impact of excess weight on your lower body creates lots of problems. You're
at higher risk for bone-thinning osteoporosis. You develop hip and back
problems. Overweight children will develop fragile bones, so they're at even higher risk
for these problems.