Human nutrition

1. COMMUNITY NUTRITION
KADIMA

2. Basic Human Needs
Nutrition

3. Definition of terms
 Nutrition – Is the process of providing or
obtaining nutrients necessary for health and
growth.
 Food – its any nutritious substance that people eat
or drink, in order to produce energy, maintain life
and growth.
 Human nutrition, process by which substances
in food are transformed into body tissues and
provide energy for the full range of physical and
mental activities that make up human life.

4. Study of human nutrition
 Human nutrition is interdisciplinary, involves
physiology, biochemistry, and molecular biology,
also fields such as psychology and anthropology,
which explore the influence of attitudes, beliefs,
preferences, and cultural traditions on food
choices.
 Human nutrition also touches
on economics and political science as the
world community recognizes and responds to the
suffering and death caused by malnutrition.

5.  The ultimate goal of nutritional science is to
 Promote optimal health and reduce the risk of chronic
diseases such as cardiovascular disease and cancer
 Prevent classic nutritional deficiency diseases such
as kwashiorkor and pellagra.
 Community nutrition :
 Its group of activities linked to applied nutrition within
the context of public health, to tailor individual and
population food patterns according to updated
scientific knowledge, in certain region with aim of
health promotion. ( Aranceta, 2001)

6. Nutrients: The Biochemical units of
nutrition
 Body requires fuel to provide energy for cellular
metabolism and repair, organ function, growth &
body movement
 Food is the fuel that keeps the machine that is our
body running

7. Energy requirements based on:
 Basal metabolic rate (BMR)-Energy needed to maintain life
sustaining ( Breathing, circulation, temperature, heart rate)
 Resting Energy Expenditure (REE)-measurement that accounts for
BMR plus energy needed to digest food & perform mild activity.
Accounts for 60-70% of our daily needs

8. Nutrients
 Elements necessary for body processes & function
 6 Categories
 Carbohydrates,
 Proteins,
 Fats, Water,
 Vitamins,
 Minerals

9. Carbohydrates
 Main source of energy (55-60% of calories in diet)
 Each gram = 4 kcal
 Composed of carbon, hydrogen & oxygen
 Functions;
 Main source of fuel (glucose) for brain, skeletal muscle during
exercise,
 RBC &WBC production,
 Cell function of renal medulla
 Energy storage – glucose converted to glycogen
 Building macromolecules ( glucose converted to ribose &
deoxyribose)
 Sparing protein metabolism

10. Functions cont..,,
 Lipid metabolism – spares lipid metabolism
 Sources;
 Obtained from plant foods, except for lactose (milk, sugar)
 bread, beans, milk, popcorn, potatoes, cookies, spaghetti, soft
drinks, corn, and cherry pie

11. Simple Carbohydrates
 Classified according to saccharides
 Monosaccharide- glucose(dextrose), fructose,
galactose (building blocks of all other CHO)
 Glucose- blood sugar (normal fasting BS=70-100
mg/ml)
 Disaccharide- sucrose, lactose, maltose,
 Sugar alcohols-sugar replacers
 Artificial sweeteners

12. Complex Carbohydrates
 Polysaccharides are complex carbohydrates
 Starches, glycogen, & fiber are polysaccharides
 Starches are the major source of CHO in diet
(grains, cereals, breads, pasta, starchy vegetables
& legumes)
 Glycogen- animal starch (found in liver & muscle
tissue, provides immediate fuel for muscle action

13. Dietary Fiber
 Plant foods that cannot be broken down by body
to digest
 Fiber eliminated by intestinal waste
 Adds volume, no fuel or energy
 Fiber in diet helps promote regularity of bowel
movements, helps in regulating blood sugar,
reducing cholesterol, may promote weight loss,
reduce risk of colon cancer & diverticular disease

15. Functions of CHO
 Provide fuel (CHO primary source)
 Spare body protein (body can convert protein to
glucose; body will break down internal protein
stores before fat stores in absence of CHO)
 Helps prevent ketosis (partially broken down fats
accumulate in blood as ketones)
 Enhance learning & memory (Glucose)

16. Proteins
 Provide a source of energy
 4 kcal per gram
 Essential for synthesis of body tissue in growth,
maintenance & repair
 Collagen, hormones, enzymes, immune cells, DNA,
RNA are composed of protein
 Blood clotting, fluid regulation, & acid-base
balance require protein

17. Protein
 Composed of carbon, hydrogen, oxygen,&
nitrogen
 There are essential and nonessential amino acids
 Complete and incomplete proteins
 Essential amino acids: isoleucine, leucine, lysine,
threonine, tryptophan, methionine, histidine,
valine, phenylalanine

18. Types of Protein
 Albumin & Insulin are simple proteins
 Lipoprotein is a complex protein (Lipid & protein)
 A lipoprotein is a biochemical assembly whose primary
function is to transport hydrophobic lipid(fat) i.e
HDL,LDL
 Complete & Incomplete proteins
 Complete proteins have all the essential amino
acids our bodies need. I.e – animal proteins.
 Incomplete proteins don't include all the
essential amino acids.

19. Protein
 Nitrogen balance- intake & output of nitrogen
equal
 When intake of nitrogen exceeds output, body is in a
positive nitrogen balance (growth, pregnancy,
maintenance of lean muscle mass & vital organs,
wound healing
 The extra nitrogen is used for building, repairing,
& replacement of tissues

20. Protein
 Negative Nitrogen balance- Body loses nitrogen
faster than it gains it
 Infection, Sepsis, Fever, starvation, head injury, trauma,
burns
 Increased nitrogen loss is the result of body tissue
destruction or loss of nitrogen containing body fluids

22. How protein functions in the body
 Provision of structure
 Growth & maintenance of tissue
 Regulation of body processes (hormones, enzymes,
nucleoproteins)
 Development of immunity
 Circulation of blood and nutrients
 Backup source of energy
 Maintains Proper pH. ...
 Balances Fluids. ...

23. Fats
 Fats(lipids) are the most calorically dense
 Composed of carbon, hydrogen, & oxygen (basic
structural unit=glycerol)
 9 kcal per gram
 Composed of monoglycerides, diglycerides, &
triglycerides
 Lipogenesis- Synthesis of fatty acids

24. Fats
 Fatty acids can be Saturated or Unsaturated,
Monounsaturated, or polyunsaturated & Trans-
fatty acids
 Essential Fatty Acids (Omega-3 fatty acids are found in
foods) must be supplied by diet
 Nonessential fatty acids(linoleic, linolenic)
 Necessary for metabolic processes
 HDL vs LDL

26. Fats
 Animal fats are high in saturated fatty acids
 Vegetable fats are high in unsaturated and
polyunsaturated fatty acids
 Sources;
 Animal fats.
 Butterfat: This is usually obtained from cow's milk
 Fish oils. ...
 Cod liver oil: This is derived from liver of cod fish. ...
 Vegetable oils.

27. Functions of Fats
 Fuel source
 Vehicle for fat soluble vitamins
 Satiety value
 Sources of essential fatty acids
 Organ protection
 Lubrication
 Insulation
 Cell membrane structure

28. Cholesterol
 Not a true fat, classified as a sterol
 Body manufactures 1000 mg day
 Component of bile salts, essential component of
cell membrane, necessary for production of
several hormones (cortisone, estrogen adrenaline,
testosterone)
 Elevated blood levels is a major risk factor for CAD
( < 200 mg/dL optimal)

30. Water
 A colorless, transparent, odorless liquid found in
seas, lakes, rivers, rain & is the basis of fluids of
living organisms.
 Functions;
 Critical component of body
 Cell function depends on a fluid environment, 60-70%
of body weight
 Muscle contains more water than fat
 Infants have higher total body water
 Fluid needs met by ingesting fluids & solid food high in
water content (fruits & veggies)

31. Vitamins
 Organic substances present in small amounts in
food
 Essential for normal metabolism
 Body depends on dietary intake
 Vitamin content higher in fresh foods
 Classification by solubility: water or fat

32. Vitamins
 Fat Soluble- Vitamins A, D, E, K
 Can be stored in body
 Provided through dietary intake except for Vitamin D
 Antioxidant role of vitamins
 Water Soluble-Vitamin C, B Complex (8 vitamins)
 Cannot be stored in body, provided by dietary intake
 Vitamins are catalysts in biochemical reactions

33. Functions of Fat-Soluble Vitamins
 Vitamin A: vision, healthy epithelial tissue, proper bone
growth, energy regulation
 Vitamin D: promotes normal bone mineralization, plays a
role in calcium and phosphorus absoprtion
 Vitamin E: antioxidant role (protects Vitamin A &
unsaturated fatty acids from oxidation
 Vitamin K: blood clotting, bone metabolism

34. Functions of Water-Soluble Vitamins
 Vitamin C: collagen synthesis, powerful
antioxidant, adrenal gland function, iron
absorption, folic acid conversion
 B-Complex: co-enzyme in numerous metabolism
mechanisms
 cell health, growth of red blood
cells,energy levels.
 good eyesight,healthy brain
function,good digestion.
 healthy appetite, proper nerve function.

35. Minerals
 Inorganic elements essential to the body as
catalysts in biochemical reactions
 Macrominerals-Body requires 100mg or more
 Trace elements-Body needs less than 100 mg

36. Minerals
 Macro minerals- Calcium, Sodium, Potassium,
Phosphorus, Magnesium, Sulfur, and Chloride
 Trace Elements- Iodine, Fluoride, Iron, Selenium,
Zinc, Copper, Selenium, Manganese, Chromium

37. Macro minerals
 Calcium
 Calcium is top macro mineral for bone & teeth.
 Sources;
 dairy products, such as milk, cheese, and yogurt
 canned salmon and sardines with bones
 leafy green vegetables, such as broccoli
 calcium-fortified foods — from orange juice to cereals
and crackers

38. Macro mineral cont..,
 Potassium
 Keeps your muscles and nervous system working
properly.
 Sources;
 Bananas, tomatoes
 potatoes and sweet potatoes, with skins
 green vegetables, such as spinach and broccoli
 citrus fruits, like oranges, low-fat milk and yogurt
 legumes, such as beans, split peas, and lentils

39. Micro minerals
 Iron
 The body needs iron to transport oxygen from
your lungs to the rest of your body.
 Source;
 meat, especially red meat, such as beef
 tuna and salmon, eggs
 Beans, baked potato with skins
 dried fruits, like raisins
 leafy green vegetables, such as broccoli

40. Micro minerals cont..,
 Zinc
 Zinc helps your immune system. It also helps with
cell growth and helps heal wounds, such as cuts.
 Source;
 beef, pork, and dark meat chicken
 nuts, such as cashews, almonds, and peanuts
 legumes, such as beans, split peas, and lentils

41. Digestion
 Mechanical breakdown that results from chewing,
churning, mixing with fluid, & chemical reaction till
food reaches it’s simplest form
 Enzymes speed up chemical reactions

42. Digestion
 Dysphagia- Difficulty swallowing
 Absorption occurs in small intestine- primary
absorption site for nutrients
 Main source of water absorption via intestine,
small intestine reabsorbs 9.5 L

45. Metabolism
 Catabolism- Breakdown of biochemical substances
into simpler substances (starvation)
 All body cells except RBC & neurons can oxidize
fatty acids into ketones for energy in the absence
of dietary CHO

46. Metabolism
 Biochemical reaction with cells
 Anabolic or Catabolic
 Anabolism- Building of more complex substances,
occurs when lean muscle is added through diet &
exercise
 Amino acids are anabolized into tissue, hormones,
& enzymes

47. Dietary Guidelines
 Recommended dietary allowances
 Food Guidelines-Food Pyramid
 Daily values on food labels (based on 2000
kcal/day)