Food is the basic necessity of man. It is a mixture of different nutrients such as carbohydrate, protein, fat, vitamins and minerals. These nutrients are essential for growth, development and maintenance of good health throughout life. They also play a vital role in meeting the special needs of pregnant and lactating women and patients recovering from illness.
FUNCTIONS OF FOOD
Food may be classified according to their functions in the body.
Physiological functions of food
1.Energy yielding foods
Foods rich in carbohydrates and fats are called energy yielding foods. They provide energy to sustain the involuntary processes essential for continuance of life, to carry out various professional, household and recreational activities and to convert food ingested into usable nutrients in the body. The energy needed is supplied by the oxidation of foods consumed. Cereals, roots and tubers, dried fruits, oils, butter and ghee are all good sources of energy.
2. 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 sources of protein but the protein is not of high quality. These foods help to maintain life and promote growth. They also supply energy.
3. Protective and Regulatory foods
Foods rich in protein, minerals and vitamins are known as protective and regulatory foods. They are essential for health and regulate activities such as maintenance of body temperature, muscle contraction, control of water balance, clotting of blood, removal of waste products from the body and maintaining heartbeat. Milk, egg, liver, fruits and vegetables are protective foods.
Social functions of food
Food has always been the central part of our community, social, cultural and religious life. It has been an expression of love, friendship and happiness at religious, social and family get-together.
Psychological functions of food
In addition to satisfying physical and social needs, foods also satisfy certain emotional needs of human beings. These include a sense of security, love and acceptance. For example, preparation of delicious foods for family members is a token of love and affection.
- ICMR FIVE FOOD GROUPS
Five Food Group Systems
|Food Group||Main Nutrients|
|I. Cereals, Grains and Products :
Rice, Wheat, Ragi, Bajra, Maize, Jowar, Barley, Rice flakes, Wheat Flour.
|Energy, protein, Invisible fat Vitamin B1, Vitamin – B2, Folic Acid, Iron, Fibre.|
|II. Pulses and Legumes :
Bengal gram, Black gram, Green gram, Red gram, Lentil (whole as well as dhal) Cowpea, Peas, Rajma, Soyabeans, Beans
|Energy, Protein, Invisible fat, Vitamin –B1, Vitamin – B2, Folic Acid, Calcium, Iron, Fibre.|
|III. Milk and Meat Products :
Milk, Curd, Skimmed milk,Cheese
Chicken, Liver, Fish, Egg, Meat.
|Protein, Fat, Vitamin –B12, Calcium.
Protein, Fat, Vitamin –B2
|IV. Fruits and Vegetables :
Mango, Guava, Tomato Ripe, Papaya, Orange. Sweet Lime, Watermelon.
|Carotenoids, Vitamin –C, Fibre.|
|Vegetables (Green Leafy) :
Amaranth, Spinach, Drumstick
leaves, Coriander leaves, Mustard
leaves, fenugreek leaves
|Invisible Fats, Carotenoids, Vitamin –
B2, Folic Acid, Calcium, Iron, Fibre.
|Other Vegetables :
Carrots, Brinjal, Ladies fingers, Capsicum, Beans, Onion, Drumstick, Cauliflower.
|Carotenoids, Folic Acid, Calcium, Fibre|
|V. Fats and Sugars :
Butter, Ghee, Hydrogenated oils,
Cooking oils like Groundnut,
|Energy, Fat, Essential Fatty Acids|
Significance of the five-food group system
The five food group system can be used for the following purposes:
- Planning wholesome balanced menus to achieve nutritional adequacy.
- Assessing nutritional status – a brief diet history of an individual can disclose inadequacies of food and nutrients from any of the five groups.
Based on the assessment, nutrition education can be imparted to the individual.
- FOOD PYRAMID
The food guide pyramid was introduced in 1992 by USDA (United States Department of Agriculture) as a general plan of what to eat each day. The food guide pyramid is a valuable tool for planning a health promoting diet. By incorporating the principle of balance, variety and moderation, an individual can still eat their favorite foods while following the food guide pyramid.
Food guide pyramid
It means choosing food from different food groups.
This means including different foods within each food group. For eg. consuming a variety of fruits.
- This means keeping serving sizes reasonable. This involves self control.
- The food guide pyramid provides recommendation for the number of daily servings that should be consumed from each of the food groups.
BALANCED DIETS FOR ADULTS
|Food item||Adult Man||Adult Woman|
|Sedentary work||Moderate work||Heavy work||Sedentary
|Cereals and millets||470||550||750||370||450||575|
|Roots and tubers||50||60||80||50||50||60|
|Fats and oils||30||40||45||20||25||30|
|Sugar / Jaggery||30||40||50||25||30||30|
BALANCED DIETS FOR CHILDREN AND ADOLESCENTS
Age in years
Age in years
|Cereals and millets||180||275||285||335||300||410||340||460||325|
|Roots and tubers||10||20||30||30||30||50||50||50||50|
|Fats and oils||15||25||30||30||30||50||40||50||40|
|Sugar / Jaggery||30||40||50||40||40||40||40||50||50|
(For non-vegetarians substitute one pulse portion with one portion (50 g) of egg / meat / chicken / fish.