Nutrition Health

Nutrition may be defined as the science of food and its relationship to health. It is concerned primarily with the part played by nutrients in body growth, development and maintenance.

(1). The word Nutrient or "food factor" is used for specific dietary constituents such as proteins, vitamins and minerals. Dietetics is the practical application of the principles of nutrition; it includes the planning of meals for the well and the sick. Good nutrition means "maintaining a nutritional status that enables us to grow well and enjoy good health"

(2). The subject of nutrition is very extensive. Since our concern is with community aspects of nutrition, the subject will be dealt with in five sections: dietary constituents, nutritional requirements, assessment of nutritional status, nutritional problems in public health and nutritional programmes in India.

Changing concepts

Through centuries, food has been recognized as important for human beings, in health and disease. The history of man to a large extent has been a struggle to obtain food. Until the turn of the nineteenth century the science of nutrition had a limited range. Protein, carbohydrate and fat had been recognized early in the 19th century as energy-yielding foods and much attention was paid to their metabolism and contribution to energy requirements (3). The discovery of vitamins "rediscovered" the science of nutrition. Between the two World Wars, research on protein gained momentum. By about 1950, all the presently known vitamins and essential amino acids had been discovered. Nutrition gained recognition as a scientific discipline, with roots in physiology and biochemistry. In fact nutrition was regarded as a branch of physiology and taught as such to medical students.

Great advances have been made during the past 50 years in knowledge of nutrition and in the practical application of that knowledge. Specific nutritional diseases were identified and technologies developed to control them, as for example, protein energy malnutrition, endemic goitre, nutritional anaemia, nutritional blindness and diarrhoeal diseases.

While attention was concentrated on nutritional deficiency diseases during the first decades of the century, the science of nutrition was extending its influence into other fields agriculture, animal husbandry, economics and sociology. This led to "green revolution" and "white revolution" in India and increased food production. However, studies of the diets and state of nutrition of people in India showed that poorer sections of the population continued to suffer from malnutrition despite increased food production. One result was that for the first time the problem of nutrition began to attract international attention (3) as a cause of social problems. International activities in the field of nutrition initiated by the League of Nations, later continued by FAO, WHO and UNICEF form a striking part of the story.

Significant advances have been made during the past two decades. The association of nutrition with infection, immunity, fertility, maternal and child health and family health have engaged scientific attention. More recently, a great deal of interest has been focussed on the role of dietary factors in the pathogenesis of non-communicable diseases such as coronary heart disease, diabetes and cancer. It has been said that most nutrition scientists are far more familiar with rats than with humans. Of greater significance during recent years is that the science of nutrition has moved out of the laboratory and linked itself to epidemiology. This association has given birth to newer concepts in nutrition such as epidemiological assessment of nutritional status of communities, nutritional and dietary surveys, nutritional surveillance, nutritional and growth monitoring, nutritional rehabilitation, nutritional indicators and nutritional interventions all parts of what is broadly known as nutritional epidemiology. Epidemiological methods are now increasingly used not only in the elucidation of disease aetiology and identification of risk factors of disease, but also in the planning and evaluation of nutritional programmes. With these newer concepts and newer approaches, nutritional science has become more dynamic.

Another concept that has emerged in recent years is that nutrition is the cornerstone of socio-economic development, and that nutritional problems are not just medical problems but are "multifactorial" with roots in many other sectors of development such as education, demography, agriculture and rural development. It has become apparent that lasting improvement in the health and nutritional status of people can be brought about only through a successful attack on the basic problems of poverty and injustice. The old concept that the health sector alone is responsible for all nutritional ills of the community has faded away. It is now realized that a broad intersect oral and integrated approach of sectors of development is needed to tackle today's nutritional problems.

In the global campaign of Health for All, promotion of proper nutrition is one of the eight elements of primary health care (4). Nutritional indicators (5) have been developed to monitor "Health for All". Greater emphasis is now placed on integrating nutrition into primary health care systems whenever possible, and formulation of national dietary goals to promote health and nutritional status of families and communities.

CLASSIFICATION OF FOODS

There are many ways of classifying foods: 1. Classification by origin: a. Foods of animal origin b. Foods of vegetable origin. 2. Classification by chemical composition: a. Proteins b. Fats c. Carbohydrates d. Vitamins e. Minerals. 3. Classification by predominant function: a. Body-building foods, e.g., milk, meat, poultry, fish, eggs, pulses, nuts, and oil seeds etc. b. Energy-giving foods, e.g., cereals, sugars, roots and tubers, fats and oils. c. Protective foods, e.g., vegetables, fruits, milk. 4. Classification by nutritive value: a. Cereals and millets b. Pulses (legumes) c. Vegetables d. Nuts and oilseeds e. Fruits f. Animal foods g. Fats and oils h. Sugar and jaggery i. Condiments and spices j. Miscellaneous foods.

NUTRIENTS

Nutrients are organic and inorganic complexes contained in food. There are about 50 different nutrients which are normally supplied through the foods we eat. Each nutrient has specific functions in the body. Most natural foods contain more than one nutrient. These may be divided into:

(i) Macronutrients: These are proteins, fats and carbohydrates which are often called "proximate principles" because they form the main bulk of food. In the Indian dietary, they contribute to the total energy intake in the following proportions.

Proteins . . . . 10 to 15 per cent Fats . . . . 15 to 30 per cent Carbohydrates . . . . 50 to 80 per cent

(ii) Micronutrients: These are vitamins and minerals. They are called micronutrients because they are required in small amounts which may vary from a fraction of a milligram to several grams. A short review of basic facts about these nutrients is given below.

PROTEINS

The word "protein" by derivation means that which is of first importance. Indeed they are of the greatest importance in human nutrition. Proteins nitrogenous compounds. They are composed of carbon, are complex organic hydrogen, oxygen, nitrogen and sulphur in varying amounts. Some proteins also contain phosphorus and iron and occasionally other elements. Proteins differ from carbohydrates and fats in that they contain nitrogen, this usually amounts to about 16 per cent. Proteins constitute about 20 per cent of the body weight in an adult.

FATS

Fats are solid at 20 deg. C; they are called "oils" if they are liquid at that temperature. Fats and oils are concentrated sources of energy. They are classified as:

(a) Simple lipids, e.g., triglycerides (b) Compound lipids, e.g., phospholipids (c) Derived lipids, e.g., cholesterol

The human body can synthesize triglycerides and cholesterol endogenously. Most of the body fat (99 per cent) in the adipose tissue is in the form of triglycerides. In normal human subjects, adipose tissue constitutes between 10 to 15 per cent of body weight. The accumulation of one kilogram of adipose tissue corresponds to 7,700 kcal of energy (10).

CARBOHYDRATES

The third major component of food is carbohydrate, which is the main source of energy, providing 4 kcals per gram. Carbohydrate is also essential for the oxidation of fats and for the synthesis of certain non-essential amino acids. There are three main sources of carbohydrates, viz., starches, sugar and cellulose. Starch is basic to the human diet. It is found in abundance in cereals, roots and tubers. Sugars comprise monosaccharides (glucose, fructose and galactose) and disaccharides (sucrose, lactose and maltose). These free sugars are highly water soluble and easily assimilated. Free sugars along with starches constitute a key source of energy. Cellulose which is the indigestible component of carbohydrate with scarcely any nutritive value, contributes to dietary fibre.

The carbohydrate reserve (glycogen) of a human adult is about 500 g. This reserve is rapidly exhausted when a man is fasting. If the dietary carbohydrates do not meet the energy needs of the body, protein and glycerol from dietary and endogenous sources are used by the body to maintain glucose haemostasis.

VITAMINS

Vitamins are a class of organic compounds categorized as essential nutrients. They are required by the body in very small amounts. They fall in the category of micronutrients. Vitamins do not yield energy but enable the body to use other nutrients. Since the body is generally unable to synthesize them (at least in sufficient amounts) they must be provided by food. A well balanced diet supplies in most instances the vitamin needs of a healthy person.

Vitamins are divided into two groups:

(a) Fat soluble vitamins, viz., vitamins A, D, E and K; (b) Water soluble vitamins, viz., vitamins of the B-group and vitamin C. Each vitamin has a specific function to perform and deficiency of any particular vitamin may lead to specific deficiency diseases. For some vitamins (e.g., vitamin E), no deficiency disease is yet known. The minimum intake for the maintenance of health in respect of many of the vitamins has been determined, but the optimum intake remains somewhat speculative.

MINERALS

More than 50 chemical elements are found in the human body, which are required for growth, repair and regulation of vital body functions. These can be divided into three major groups:

(a) MAJOR MINERALS: These include calcium, phosphorus, sodium, potassium and magnesium.

(b) TRACE ELEMENTS: These are elements required by the body in quantities of less than a few milligrams per day, e.g. Iron, iodine, fluorine, zinc, copper cobalt, chromium, manganese, molybdenum, selenium, nickel, tin, silicon and vanadium (41). Many more have been added to the list in the last few years.

(c) TRACE CONTAMINANTS WITH NO KNOWN FUNCTION: These include lead, mercury, barium, boron, and aluminium.

Only a few mineral elements (e.g., calcium, phosphorus, potassium, sodium, iron, fluorine, iodine) are associated with clearly recognizable clinical situations in man. For none of the other elements do we know with any certainty for their metabolic roles, and much less the clinical effects of dietary insufficiency (42). The bio-availability of minerals such as iron and zinc may be low in a total vegetarian diet because of the presence of substances such as phytic acid. Besides, large amounts of dietary fibre may interfere with proper absorption. Man is not likely to suffer from trace element deficiencies as long as he is omnivorous. Surveys have shown that mineral deficiencies are no greater among vegetarians than among non-vegetarians. In fact, man's need for trace elements has not yet been precisely determined. Trace elements should not be used as dietary supplements, since excessive amounts can have injurious effects.

NUTRITIONAL PROFILES OF PRINCIPAL FOODS

When planning balanced diets, it is important to know what foods are available according to origin, approximate chemical composition, and predominant function and how to combine them to increase nutritive value. Since each food has a different nutritional profile, an intake of different types of foods is desired to achieve optimum health.

Problem of malnutrition

Malnutrition has been defined as "a pathological state resulting from a relative or absolute deficiency or excess of one or more essential nutrients". It comprises four forms undernutrition, over nutrition, imbalance and the specific deficiency (134).

(1) Undernutrition: This is the condition which results when insufficient food is eaten over an extended period of time. In extreme cases, it is called starvation.

(2) Over nutrition: This is the pathological state resulting from the consumption of excessive quantity of food over an extended period of time. The high incidence of obesity, atheroma and diabetes in western societies is attributed to over nutrition.

(3) Imbalance: It is the pathological state resulting from a disproportion among essential nutrients with or without the absolute deficiency of any nutrient. (4) Specific deficiency: It is the pathological state resulting from a relative or absolute lack of an individual nutrient.

On a global scale the five principal nutritional deficiency diseases that are being accorded the highest priority action are wasting, stunting, xerophthalmia, nutritional anaemias and endemic goitre. These diseases represent the tip of the "iceberg" of malnutrition; a much larger population are affected by "hidden" malnutrition which is not easy to diagnose.

The effects of malnutrition on the community are both direct and indirect. The direct effects are the occurrence of frank and subclinical nutrition deficiency diseases such as kwashiorkor, marasmus, vitamin and mineral deficiency diseases. The indirect effects are a high morbidity and mortality among young children (nearly 50 per cent of total deaths in the developing countries occur among children under-5 years of age as compared to less than 5 per cent in developed countries), retarded physical and mental growth and development (which may be permanent), lowered vitality of the people leading to lowered productivity and reduced life expectancy. Malnutrition predisposes to infection and infection to malnutrition; and the morbidity arising therefrom as a result of complications from such infectious diseases as tuberculosis and gastroenteritis is not inconsiderable. The high rate of maternal mortality, stillbirth and low birth-weight are all associated with malnutrition.

In the more developed countries of the world nutritional problems are somewhat different. Over nutrition is encountered much more frequently than undernutrition. The health hazards from over nutrition are a high incidence of obesity, diabetes, hypertension, cardiovascular and renal diseases, disorders of liver and gall bladder. From this brief review, it is obvious that the consequences of malnutrition are ominous.

COMMUNITY NUTRITION PROGRAMMES

The Government of India have initiated several large-scale supplementary feeding programmes, and programmes aimed at overcoming specific deficiency diseases through various Ministries to combat malnutrition. They are as shown in-

1. Vitamin A prophylaxis programme

One of the components of the National Programme for Control of Blindness is to administer a single massive dose of an oily preparation of vitamin A containing 200,000 IU (110 mg of retinol palmitate) orally to all pre-school children in the community every 6 months through peripheral health workers. This programme was launched by the Ministry of Health and Family Welfare in 1970 on the basis of technology developed at the National Institute of Nutrition at Hyderabad. An evaluation of the programme has revealed a significant reduction in vitamin A deficiency in children (see page 705, 706 for details).

2. Prophylaxis against nutritional anaemia

In view of its public health importance, a national programme for the prevention of nutritional anaemia was launched by the Govt. of India during the fourth Five Year Plan. The programme consists of distribution of iron and folic acid (folifer) tablets to pregnant women and young children (1-12 years). Mother and Child Health (MCH) Centres in urban areas, primary health centres in rural areas and ICDS projects are engaged in the implementation of this programme. The technology for the control of anaemia through iron fortification of common salt has also been developed at the National Institute of Nutrition at Hyderabad (see page 732 for more details).

3. Control of iodine deficiency disorders

The National Goitre Control Programme was launched by the Government of India in 1962 in the conventional goitre belt in the Himalayan region with the objective of identification of the goitre endemic areas to supply iodized salt in place of common salt and to assess the impact of goitre control measures over a period of time.

Surveys, however, indicated that the problem of goitre and iodine deficiency disorders was more widespread than it was thought earlier, with nearly 145 million people estimated to be living in known goitre endemic areas of the country. As a result, a major national programme - the IDD Control Programme was - mounted in 1986 with the objective to replace the entire edible salt by iodide salt, in a phased manner by 1992 (see page 494, 733 for more details).

4. Special nutrition programme

This programme was started in 1970 for the nutritional benefit of children below 6 years of age, pregnant and nursing mothers and is in operation in urban slums, tribal areas and backward rural areas. The supplementary food supplies about 300 kcal and 10-12 grams of protein per child per day. The beneficiary mothers receive daily 500 kcal and 25 grams of protein. This supplement is provided to them for about 300 days in a year. This programme was originally launched as a Central programme and was transferred to the State sector in the fifth Five Year Plan as part of the Minimum Needs Programme (168). The main aim of the Special Nutrition Programme is to improve the nutritional status of the target groups. This programme is gradually being merged into the ICDS programme.

5. Balwadi nutrition programme

This programme was started in 1970 for the benefit of children in the age group 3-6 years in rural areas. It is under the overall charge of the Department of Social Welfare. Four national level organizations including the Indian Council of Child Welfare are given grants to implement the programme. Voluntary organizations which receive the funds are actively involved in the day-to-day management. The programme is implemented through Balwadis which also provide pre-primary education to these children. The food supplement provides 300 kcal and 10 grams of protein per child per day. Balwadis are being phased out because of universalization of ICDS.

6. ICDS programme

Integrated Child Development Services programme was started in 1975 in pursuance of the (ICDS) National Policy for Children. There is a strong nutrition component in this programme in the form of supplementary nutrition, vitamin A prophylaxis and iron and folic acid distribution. The beneficiaries are preschool children below 6 years, and adolescent girls 11 to 18 years, pregnant and lactating mothers. The States and Union Territories are encouraged to undertake additional ICDS projects on the Central pattern to cover more beneficiaries (168).

The workers at the village level who deliver the services are called Anganwadi workers. Each Anganwadi unit covers a population of about 400 to 800 and mini anganwadi centre about 150 to 400. A network of Mahila Mandals has been built up in ICDS Project areas to help Anganwadi workers in providing health and nutrition services. The work of Anganwadis is supervised by Mukhyasevikas. Field supervision is done by the Child Development Project Officer (CDPO).

7. Mid-day meal programme

The mid-day meal programme (MDMP) is also known as School Lunch Programme. This programme has been in operation since 1961 throughout the country. The major objective of the programme is to attract more children for admission to schools and retain them so that literacy improvement of children could be brought about (167).

In formulating mid-day meals for school children, the following broad principles should be kept in mind (169).

(a) the meal should be a supplement and not a substitute to the home diet; (b) the meal should supply at least one-third of the total energy requirement, and half of the protein need; (c) the cost of the meal should be reasonably low; (d) the meal should be such that it can be prepared easily in schools; no complicated cooking process should be involved; (e) as far as possible, locally available foods should be used; this will reduce the cost of the meal; and (f) the menu should be frequently changed to avoid monotony.

The National Institute of Nutrition, Hyderabad has prepared model recipes for the preparation of school meals suitable for North and South Indians. Copies of these publications can be had gratis on request. The National Institute of Nutrition is of the view that the minimum number of feeding days in a year should be 250 to have the desired impact on the children (170).

School feeding should not be considered as an end in itself. The important goals to be accomplished are: reorientation of eating habits, incorporating nutrition education into the curriculum; encouraging the use of local commodities; improving school attendance as well as educational performance of the pupils. Since the number to be fed are in millions, the problem is one of balance between the resources and the number to be fed.

The mid-day meal programme became part of the Minimum Needs Programme in the Fifth Five Year Plan (168).

8. Mid-day meal scheme (171)

Mid-day meal scheme now known as PM Poshan Scheme is also known as National Programme of Nutritional Support to Primary Education. It was launched as a centrally sponsored scheme on 15th August 1995 and revised in 2004. Its objective being universalization of primary education by increasing enrolment, retention and attendance and simultaneously impacting on nutrition of students in primary classes. It was implemented in 2,408 blocks in the first year and covered the whole country in a phased manner by 1997-98. The programme originally covered children of primary stage (classes I to V) in government, local body and government aided schools and was extended in Oct. 2002, to cover children studying in Education Guarantee Scheme and Alternative and Innovative Education Centres also.

The central assistance provided to states under the programme is by way of free supply of food grain from nearest Food Corporation of India godown at the rate of 100 g. per student per day and subsidy for transport of food grain. To achieve the objective, a cooked mid-day meal with minimum 300 Calories and 8 to 12 grammes of protein content will be provided to all the children in class I to V. Some suggesstions for preparation of nutritious and economical mid-day meals are as under:

• Food grains must be stored in a place away from moisture, in air tight containers/bins to avoid infestation. • Use whole wheat or broken wheat (dalia) for preparing mid-day meals. • Rice should preferably be parboiled or unpolished. • 'Single Dish Meals' using broken wheat or rice and incorporating some amount of a pulse or soya beans, a seasonal vegetable/green leafy vegetable, and some amount of edible oil will save both time and fuel besides being nutritious. Broken wheat pulao, leafy khichari, upma, dal-vegetable bhaat are some examples of single dish meals. • Cereal pulse combination is necessary to have good quality protein. The cereal pulse ratio could range from 3:1 to 5:1. • Sprouted pulses have more nutrients and should be incorporated in single dish meals. • Leafy vegetables when added to any preparation should be thoroughly washed before cutting and should not be subjected to washing after cutting. • Soaking of rice, dal, Bengal gram etc. reduces cooking time. Wash the grains thoroughly and soak in just sufficient amount of water required for cooking. • Rice water if left after cooking should be mixed with dal if these are cooked separately and should never be thrown away. • Fermentation improves nutritive value. Preparation of idli, dosa, dhokla etc. may be encouraged. • Cooking must be done with the lid on to avoid loss of nutrients. • Over cooking should be avoided. • Reheating of oil used for frying is harmful and should be avoided. • Leafy tops of carrots, radish, turnips etc. should not be thrown but utilized in preparing mid-day meals. • Only "iodized salt" should be used for cooking mid-day meals.

Monitoring and evaluation of nutrition programmes

Good preventive medicine demands effective planning. Monitoring and evaluation of health programmes. An important advance in this field is the development of the randomized controlled trial for the evaluation of the effectiveness and efficiency of health care programmes. Criticism is often voiced that nutrition programmes are not based on good intentions. It is considered unethical to launch a major nutritional programme (or for that matter any other health programme) without a built-in-provision for monitoring, evaluation and feedback. Since health and nutrition of the young child is indivisible from the health and nutrition of the family as a whole, there is now increasing recognition that it is only through an improvement of the family

diet as a whole, that the diet of the young child in the poor family can be improved (172). Secondly, a question is raised: How long will a country be able to feed its children who may number 100 million or more without any socio-economic improvements? An eminent nutrition scientist in India has said: "In the long run, we can hope to improve the nutritional status of our children only through improvement in the economic conditions of the community to a level at which families can afford balanced diets. Organized State-sponsored feeding programmes cannot be the permanent answer to the problem" (84).