The document discusses the classification of foods according to their origin, function, nutritive value, and chemical composition. It describes the major macronutrients (carbohydrates, proteins, fats) and micronutrients (vitamins, minerals) found in foods, their sources, and importance for public health. Recommended dietary allowances of energy and proteins are also provided based on age, gender, and physical activity levels.

1. Dr. Anuj Singh
Asst. Professor
Community Medicine Dept.
UIMS, Prayagraj
Classification
of
Foods

2. 1
2
3
4
Learning
Objectives-
CHEMICAL
COMPOSITION
NUTRITIVE VALUE
FUNCTION
ORIGIN
Classification of
Foods by-

3. 1.
ORIGIN
Classification of Foods by-
Fruits
Vegetables
Milk
Egg
Meat
Plant Origin Animal Origin

4. 2.
FUNCTION
Carb.
& Fat
Protein
Classification of Foods by-
Milk
Meat
Egg
Fish
Pulses
Sugar
Fats & Oil
Root
Tubers
Body Building
Food
Energy Yielding
Food
Fruits
Milk
Vegetable
Vitamins
&
minerals
Protective
Food

5. Classification of Foods by-
3. NUTRITIVE
VALUE
1. Cereals & millets
2. Pulses
3. Vegetables
4. Nuts & oil
5. Fruits
6. Animal food
7. Fats & oil
8. Sugar & jaggery
9. Condiments &
spices
10. Miscellaneous
foods

6. Classification of Foods by-
4.
CHEMICAL
COMPOSITION
2
1 CARBOHYDRATE
PROTEINS
3 FATS
4 VITAMINS & MINERALS
4 DIETARY FIBERS

7. MACRONUTRIENTS MICRONUTRIENTS
•CARBOHYDRATES
•PROTEINS
•FATS
“PROXIMATE
PRINICIPLES OF
DIET”
Forms the bulk of
diet
•VITAMIN S
&
• MINERALS
Required in small
quantities
NUTRIENTS

8. MACRONUTRIENTS
“PROXIMATE PRINICIPLES OF DIET”
Forms the bulk of diet
Energy yeild-
CARBOHYDRATES 4 Kcal per gram (17 KJ)
PROTEINS 4 Kcal per gram (17 KJ)
FATS 9 Kcal per gram (37 KJ)

9. MICRONUTRIENTS
•Vitamins & Minerals
•Required in small quantities
Major minerals Sodium, Potassium, Magnesium, Calcium,
Phosphorus
Trace elements Iron, Iodine, Zinc, Copper, Cobalt, Chromium,
Selenium, Nickel, Vanadium, Silicon
Trace
contaminants
Lead, Mercury, Barium, Boron, Aluminium
(No known function in body)

10. CARBOHYDRATES:
Carbohydrates (Sugar & Starches) are the most efficient
source of energy and are known as the “fuel of life”
Spare protein for growth & repair
In a balanced diet, 60% of our daily calorie requirement
should come from carbohydrates (50-70%)
Sources: Rice, white bread, Oats, potato, banana, corn

11. CARBOHYDRATES: Cont..
•Glycaemic index-
is defined by the area under the two-
hour blood glucose response curve following the ingestion of
a fixed proportion of test carbohydrate(50g) as proportion (%
of the AUC of the standard)
•Public Health Importance: GI of food is used for
control and management of Diabetes mellitus

12. PROTEINS:
Protein are the “building blocks” of body
Proteins are required for growth, maintenance &
replacement of body cells
Sources:
• Animal source-Milk, milk products egg, meat, fish, liver
Better quality, readily absorbed & utilized by body
•Plant source- Cereals, pulses, dry fruit, nuts, bean etc
Daily requirement: 0.83g/kg body weight/day

13. PROTEINS: cont..
Proteins are made up of amino acids.
Some 20 amino acids are needed by human body, of which
9 are called essential amino acids because they can not by
synthesized in the body, therefore they must be obtained
from dietary proteins
List of Essential amino acids:
1. Leucine 5. Phenylalanine
9. Histidine
2. Isoleucine 6. Threonine
3. Lysine 7. Valine
4. Methionine 8.Tryptophan

14. •Public Health Importance: PEM

15. FATS:
Fats are solid at 20 deg.C; they are called “oils if they are
liquid at the room temp.
They are classified as:
a) Simple lipids, e.g., triglycerides
b) Compound lipid, e.g., phospholipids
c) Derived lipids, e.g.,Cholesterol
Sources: Milk, egg, meat, fish, oil, ghee

16. Fats on Hydrolysis yields= Fatty acids & glycerol
Fatty acids
•Saturated fatty acid •Unsaturated fatty acid
MUFA
PUFA

17. Essential Fatty Acids:
Essential fatty acids are those that cannot be synthesized in
human body : they can be only supplemented from the food
Most important EFA: Linoleic acid, which serves as a basis
for production of other EFA

18. Essential Fatty Acids:
Examples of EFA-
1 Alpha-Linoleic acid 5 Archiodonic acid
2 Eicosapentaenoic acd 6 Gama-Linolenic acid
3 Docosahexaenoic acid 7 Dihomo-gamma-Linolenic acid
4 Linoleic acid

19. •Public Health Importance:
Fats

20. Classification of Vitamins-

21. Classification of Minerals-

22. DIETARY FIBERS
• “Dietary fibre is the remnants of the
edible part of plants that are
resistant to digestion and absorption.
Role:
 Soften & increases the stool bulk
 Decreases blood glucose &
cholesterol

23. Vitamins , minerals deficiency &
disorder:

24. Important Definition
Balanced Diet :
Diet containing a variety of food; in such quantities and
proportions that the need for energy and nutrients are adequately
met.
•Composition of balanced diet: Total daily energy intake by-
Proteins : 10-15%
Fats : 15-30%
Carbohydrates : 50-70%

25. Important Definition
Recommended Dietary Allowance (RDA):
• is a level of intake corresponding to Mean +2 Standard
Deviation, which covers requirements of 97.5%.
• RDA safe level approach NOT USED FOR PREGNANCY

26. WORK M (Adult) Proteins
( g/d)
F (Adult) Proteins
( g/d)
Sedentary
worker
2110
54
1660
46
Moderate
worker
2710 2130
Heavy worker 3470 2720
Pregnancy +350 9.5-22
Lactation (0-6m) +600 +17
Lactation (6-12m) +520 +13
Recommended Daily Energy, protein intake-ICMR 2020