Nutritional Guidelines
MEANS OF ENERGY
The energy requirement of a person depends on various factors. The most important factor in assessing the energy requirement is the basal metabolic rate of the person.
Basal Metabolic Rate (BMR) : This is defined as the amount of heat or energy required by the body to do the involuntary work of the body. Functions of brain, heart, liver, kidneys, lungs, secretary activities of the glands and intestinal movements are the basal activities in our body.
Factors Affecting the BMR : Basal metabolic rate of a person depends on the size, shape, composition, body weight, age and physiological condition of the person. Nutritional status and endocrine system of the body also exert their influence on basal metabolic rate of a person. Climatic condition of the surroundings also affects the basal metabolic rate.
Size: Since the heat loss in body is proportional to the skin surface, a tall and thin person has greater surface and thus higher basal metabolic rate compared to the short person. The body composition shows variations in energy use. With little fat deposition in the body the basal metabolic rate increases and thus a tall, thin person has higher rates of basal metabolism compared to a short, fat man. Constant muscular activities of an athlete demand about 5 per cent more basal metabolic rate.
Sex: Sex also makes a variation in energy requirement. The metabolic rate of women is 6-10 per cent lower than that of men.
Growth Period: During the growth period the basal metabolic rate and thus the energy requirement are increased. The highest BMR is during the first two years. After the growth period, especially after 25 years of age, there is a decline in energy requirement.
Endocrine Glands: The thyroid gland exerts influence over energy requirements. Thyroid hyperactivity will speed up basal metabolism. The pituitary gland also increases the metabolic fate if it has disturbance. Adrenaline increases the BMR.
Nutritional Status: During undernourishment the basal metabolic rate also declines to an extent of thirty per cent.
Pregnancy Condition: During pregnancy and lactation the basal metabolic rate is increased by about 5 per cent during the first and second trimester and 12 per cent during the third trimester.
Sleep: During sleep the BMR is less than in the waking state.
Climate: Climatic conditions of the environment also affect the energy requirement. If the temperature falls below 14°C the energy requirement increases.
Body Temperature: Fever increases the BMR.
Disease Conditions : Diseases like typhoid fever, medullary diseases and lymphatic leukaemia show an increase in the BMR.
Physical Activities: Physical activities half an hour before BMR measurement show high rates of BMR.
Total energy requirement of 4 person varies according to the basal metabolic rate, effect of food, activity involved, age, sex, physiological conditions and climatic conditions of the surroundings.
Energy requirements of an adult in India was reviewed by "The Expert Group" of the FAO/WHO in terms of a reference man and reference woman. The reference man is in the age group of 20-39 years, with a weight of 55 kgs, without any disease and with a capacity to perform 8 hours of moderate activity. When not engaged in work a reference man spends 8 hours in bed and 4-6 hours in moving around or in a sitting position and 2 hours either walking or doing household activities.
In the case of a reference woman, the difference is only in her body weight that is, as against 55 kg of a man she weighs 45 kg. Instead of the physical activity of the occupation, the woman does household duties. Other conditions are the same in the case of a reference woman.
The energy expenditure for man and woman is calculated considering their internal and external activities. The FAO/WHO expert group (1983) suggested some recommendations as given in Table.
Additional requirement of energy is needed for the growth of the foetus, placenta and maternal tissues during pregnancy.
The BMR is also increased due to increased internal activities. Daily 150 kcals during the first trimester and 300 kcals during the rest of pregnancy is recommended.
The energy cost during the term of pregnancy is 62,500 kcals. Additional energy requirement during lactation is for the secretion of milk. For a normal output of 850 ml of milk during the first 6 months 550 kcals/day is recommended.
During infancy the energy requirement is high. For 0-3 months 120 kcalsAg, 3-5 months 115 kcals/kg, 6-8 months 110 kcal/kg, 9-11 months 105 kcal/kg and at one year 112 kcals are recommended.
For children, the energy requirement varies according to their body weight The ideal weight of the children according to their age must be considered for assessing energy requirements.
Thus in the latest recommendations, some suggestions were made as shown in Table.
The activities which demand maximum energy are in the following order: Walking very fast, severe exercises, running, swimming, sawing wood, labourer’s work, carpentry, metal and industrial work, walking slowly, laundry work, typing and ironing.
DIET PLAN
Planning a balanced diet within the income level needs precise knowledge about the sources of nutrients, their requirements for various groups, seasonal availability of various foodstuffs and dietary habits of the group.
Blending these theoretical knowledge into a day’s menu needs skill which has to be acquired through practice. There are certain basic principles which has to be observed while planning a balanced diet. As the name indicates a planned diet should be balanced. A diet is called balanced when all the nutrients required by the body are present in correct proportion. A judicious selection from the food groups will supply adequate nutrients for maintenance, repair and growth.
Other factors to be considered are composition of the family and the physiological phases of family members, dietary habits of the family, food budget of the family, variety in meal patterns, appearance, texture and taste of meals, selection of food for seasons (cold and hot climate condition) and nutritional balance.
While planning a diet, the composition of the family has to be considered. Infants, children, teenagers, pregnant and lactating mothers and geriaric people need food in different amounts. There are variation in their nutritional requirements and their digestive capacity. Quality and quantity and often the preparation need certain changes. A careful planning gives provisions for all these without making great changes in the preparation pattern of foods.
Dietary habits of the family also have to be considered while meal planning. Food habits are influenced by earlier experiences in life: sensory, aesthetic, economic, geographic, social and cultural factors. Often food habits change according to the new environment, new values and availability of items. When a child is exposed to group feeding practices slight changes in likes and dislikes of foods are common. Age and sex also influence food choices.
The best example is an adolescent’s dietary habits. There are vegetarian, non-vegetarian, lacto-aro-vegetarian and pesco-vegetarian dietary habits (plant foods and fish but no milk, egg, meat or poultry).
Food budget is a very important factor in meal planning. Money available to buy food items, time available for food preparation, job pattern, life-style of the family members, location of residence, and family values decide how much has to be spent on food. First of all to reduce food expenditure, one must have an idea about low cost nourishing foods for selection. Intelligent selection, good marketing, just enough bulk purchase, seasonal buying, food processing and preservation, better food preparation methods, avoiding more indulgence in ready-to-eat foods, fast foods, readymade food and hotel catering reduce food budget.
Variety in meal makes eating a pleasure. The same meal, if repeated, creates monotonous taste and reduces appetite. Variety in choice of food items, methods of preparation in colour, texture and flavour induce appetite and provide satiety value to the meal. When food is prepared in a proper form with characteristic taste and flavour, it derives satiety value.
Above all these factors, a nutritional balance in each meal is essential. Successful meal planning principles suggest that each meal must be nutritionally balanced. One-third of the total nutrients must be in the lunch, one-third in the dinner and the remaining one-third in breakfast and teatime. Skipping a meal is not good. Many people often skip breakfast which is very bad as far as the body is concerned. Studies have showed that the performance of a person after mid-morning is very poor if they skip their breakfast.
Based on these principles, if a diet is planned it will be a balanced one. The Indian Council of Medical Research has suggested the amounts of various food items to make a balanced diet for various groups.
Millets, cereals, roots and tubers, pulses and leafy vegetables can be included liberally. Cheap seasonal fruits and salad vegetables lend attraction and freshness to the diets. Balanced diets of middle income groups can include moderate amounts of protective and proteins-rich food. Milk, egg, fish and meat can be included in moderate amounts while pulses, nuts, fruits and other foods can be used in liberal amounts.
Balanced Diets for High Cost : In a high cost diet protect the foods and protein-rich foods can be included liberally. Wet surveys in India have shown that malnutrition is prevalent among high class people also. B vitamins and certain minerals are not included m enough quantities in their dietaries. Over-nutrition due to high consumption of milk, meat, fats, ghee and sweets are common.
The ultimate aim of consuming food is to maintain health. There is no single foodstuff which can contribute all the nutrients needed by the body. Only a judicious selection can provide all the nutrients in required amount. In order to select the sources of all nutrients and that also in correct proportion one must know about the basic principles of food selection. The nutritionists and food scientists all over the world have put in a lot of efforts to formulate certain guidelines in these matters. Basic food groups suitable to different countries were evolved by the nutritionists.
The US Department of Agriculture suggested a number of food group plans like the Basic-4 food group.
The Basic-7 Food Group and the Basic-11 Group Plan : The Nutrition Expert Group of L.C.M.R. (India) suggested a fivefood group plan.
Based on their nutritive values foods are grouped into 11. They are:
1. Cereals and millets
2. Pulses (legumes)
3. Nuts and oil seeds
4. Vegetables
5. Fruits
6. Milk and milk products
7. Egg
8. Meat, fish and other fleshy foods
9. Fats and oils
10. Sugar and jaggery
11. Spices and condiments.
Cereals and Millets : They supply the major portion of calories (70%), more than 50 per cent of B Vitamins. In a poor vegetarian diet cereals supply more than 70 per cent of protein.
Rice and wheat are abundantly used as staple cereals in the world. In India rice is used mainly in the diet of South India, whereas wheat is the main staple in all other parts.
The major millets used are jowar, ragi and bajra. Though they are cheaper they are superior in their mineral supply and protein content Ragi is a very good source of calcium.
Pulses and legumes are fair sources of proteins and they are good sources of B vitamins, especially thiamine and riboflavin. Quantitatively their protein content is high but qualitatively they are not as superior as animal proteins. But in an Indian diet cereals and pulses supplement mutually in their amino acid content and improve the quality of protein. Pulses and legumes are comparatively cheap sources of protein. Cowgram, horsegram, soyabean, dry field beans and dried peas are some of the cheap pulses.
Nuts and oilseeds are fair sources of protein. Coconut is a good source of energy. It has also fair sources of B vitamin. Vegetables are unique in their vitamins and mineral content. Vegetables are again grouped into yellow vegetables, leafy vegetables and as other vegetables. Yellow vegetables and leafy vegetables are rich sources of vitamin ‘A’ (carotene), calcium, iron, folic acid, riboflavin and vitamin ‘C. But the iron content in vegetables is comparatively poorly utilised by the body. Other vegetables are good sources of minerals like calcium, trace elements and vitamin C.
Apart from these, vegetables have a high percentage of water in them. They contribute the alkaline ash and the bulk or cellulose to the body. Beetroot, carrot and ladyfinger are high in sodium content. Fruits, especially citrus fruits, are good sources of ascorbic acid. Some starchy fruits are rich in fructose and dextrose; yellow fruits contribute carotene, the provitamin.
A Fruits as a group supply water and electrolytes like potassium. Most of the fruits are rich sources of potassium and poor sources of sodium. Dates, dry raisins, grapes, peaches, lime and ripe papaya are very high in their potassium content Bananas are rich in starch content in the raw form and in sugar content in the ripe form.
Milk and milk products are the best sources of calcium and ribo-flavin and second to the meat groups in protein content. Except a iron and vitamin ‘C milk is good in all other nutrients. Milk products are high in biological value and milk cream is excellent in vitamin A.
Egg has biologically very good protein. Egg white is rich in protein and egg yolk is rich in fat, iron, sodium, potassium, calcium and magnesium. Vitamins like thiamine, riboflavin, vitamins A and D are also present in egg. It plays very many roles in cookery.
Meat, fish and other flesh foods rank first in protein content. They are also good sources of phosphorous, magnesium, iron, thiamine, niacin, B 6, and B 12. The biological value of meat protein is high. Fat is present in a good quantity in it.
Fats and oils contribute mainly calories and they are good sources of essential fatty acids and vitamins A and E.
Sugar and jaggery are the common sweetening agents in our diet. They are rich sources of carbohydrate.
Spices and condiments are necessary foodstuffs used for flavouring foods. Apart from these functions some of them contribute certain nutrients. Red chillies and coriander supply carotene; green chillies vitamin ‘C turmeric and tamarind iron; and garlic stimulates synthesis of certain vitamins.
Then food is classified into 11 groups for convenience in selection.
But in different countries different food group plans are followed by the nutritionists to formulate a balanced diet.
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