Diet plays a very important role in the successful practice of yoga. There is a saying, “the healthy man satisfies his hunger when he eats, the sick man satisfies his appetite.” In fact “we are what we eat” — this statement is very true in more than one sense. Food is of course necessary for our physical well being, but it exerts an equal effect on our mental state. Since the outcome of mental process has direct bearing on our physical health, we cannot take it (diet) as an instrument affecting physical health only.
In the recent times people are becoming more conscious about their diet and dietary habits. Modern food items like hamburgers, pizzas, jams, jellies, cola-drinks, chocolates, ice-creams, noodles etc. have gained excessive popularity due to publicity through media. It has been publicised through electronic media that such foods are much more convenient, economic, easy to -procure and have so-called nutritive value too. In addition to that, canned, refined, frozen, artificially flavoured fast foods are becoming much popular among all the categories of people.
Use of such foods is becoming a status symbol. It is a well-known fact that nature has provided us several nutritious edible foods in their natural form; still the people are running behind the false propaganda about so-called ‘Junk-foods’, without knowing about the hidden danger. It is necessary to know about the dietary habits and nurtitional requirement of our body. A brief account of nutrients and their functions, dietary patterns and digestive process is being given here.
Nutrients
Man needs a wide range of nutrients to perform various functions in the body and to lead healthy life. These nutrients include protein, fat, carbohydrate, vitamins and minerals.
These are chemical substances present in the food items. Different food items contain various nutrients in various proportions. Depending on the relative concentration of these nutrients foods are classified as protein-rich foods, carbohydrate — rich foods and fat-rich foods etc. Some foods provide only a single nutrient as in case of sugar, which is a source of only carbohydrate, whereas oils, ghee etc. provide only fats.
Carbohydrates: Carrohydrates are a class of energy yielding substances, which include starch, glucose, cane sugar, milk etc. Cereals are the main source of carbohydrates. Grain foods, roots and tubers are largely composed of starch, a complex carbohydrate. Food ingredients like simple sugars, namely cane sugar and glucose, are pure carbohydrates. Starch is a complex carbohydrate made up of glucose units. Glucose derived from starch and other sugars present in the diet is the main source of energy in the body. Carbohydrates derived from cereals form the chief source of energy in Indian diets. Starches when eaten in cooked form are completely digested in the gastrointestinal tract, and the released glucose is absorbed and metabolised in the body to yield energy.
Many other food items contain non-digestible carbohydrates like cellulose, hemicellulose, gums, pectins and lignins. These undigestible carbohydrates are designated dietary fibre or unavailable carbohydrates. These are not digested in the digestive tract and most of them are voided as such and thus contribute to the bulk of stool. Though they do not contribute to the nutritive value of foods, the presence of fibres, i.e. roughages, in the diet is necessary for the mechanism of digestion and elimination of water. The contraction of muscular walls of the digestive tract is stimulated by the fibre, thus counteracting the tendency to constipation. Lack of adequate dietary fibre in diets containing refined foods leads to constipation and intestinal cancer.
Some of the dietary fibres like gums and mucilages in our diets have been shown to lower the blood-cholesterol and blood glucose levels. Vegetables, particularly the leafy ones, fresh fruits and unrefined cereals, are comparatively rich in fibre and a generous inclusion of these helps avoid constripation.
Fats: Fat is an important component of diet and serves a number of functions in the diet. It is a concentrated source of energy and it supplies per unit weight more than twice the energy furnished by either protein or carbohydrate. It also imparts palatability to a diet and retards stomach-emptying time. Presence of fat in the diet is important for the absorption of fat-soluble vitamins like vitamin-A and beta-carotene present in the diet. Apart from these functions, some fats, particularly those derived from vegetable sources, provide what is known as essential fatty acids, which have vitamin-like functions in the body. Fats also form protective layers, which shield the delicate body organs from injury and allow storage of energy for future use. Oil and ghee are the main sources of fat.
In recent years there has been a revival of interest in the nutritional aspects of fats. The excessive intake of fat in diet increases the level of cholesterol in blood, which gradually leads to its being deposited under the lining of blood vessels, resulting in the condition known as atherosclerosis, in which the blood vessels are narrowed and hardened. The coronary arteries supplying blood to the heart are affected, leading to coronary heart disease (CHD).
In deciding the desirable level • of fat in the diet, the following facts must be kept in mind:
(a) the minimum amount of fat to meet the essentia! fatty acid requirement
(b) the amount needed to promote absorption of fat-soluble vitamins
(c) providing palatability to food
(d) the undersirable effect of excessive intake of fat.
Proteins: Proteins are vital to any living organism. They are important constituents of tissues and cells of the body. They form the important component of muscle and other tissues and vital body fluids like blood. The proteins in the form of enzymes and hormones are concerned with a wide range of vital metabolic processes in the body. Proteins supply the body building material and make good the loss that occurs due to wear and tear. Proteins as antibodies help the body in defending against infection. Thus proteins are vital to the living process and carry out a wide range of functions essential for the sustenance of life and for sound health. The proteins needed by the body have to be supplied through the diet we consume. The adequacy of protein in the diet is an important measure of adequacy and quality of a diet.
Although most of the foods contain protein to varying degree, pulses, milk and milk products, oilseeds, nuts, meat, fish and eggs are the major sources of protein. In the vegetarian system of diet, pulses and milk are such an important source of protein, which is not only under reach of a common man, but also constitute most suitable food for the health of both body and mind.
Biological value of proteins: In judging the adequacy of dietary proteins to meet the human needs, not only the quantity, but the nutritional quality of the dietary proteins also matters. Proteins present in different foods vary in their nutritional quality because of differences in their amino acid composition. Amino acids are the building blocks of proteins. There are 22 of them in proteins, nine being designated as essential amino acids, since they cannot by synthesised in the body.
The rest of the amino acids are called non-essential as they can be formed in the body by interconnections of other essential amino acids or synthesised from other simple compounds. The quality of dietary protein depends on the pattern of essential amino acids it supplies. The best quality protein is the one that provides essential amino acid pattern very close to the pattern of tissue protein. Thus biological value of a particular protein depends upon absorption and net protein utilization.
2. Protein requirement : Proteins are required for general maintenance, to replace the wear and tear in tissues in adults; for growth in infants and children; for foetal development in pregnancy and milk output during lactation. The relative requirements of proteins of the latter groups are higher than of adults. The actual amount of protein to be consumed daily to meet the above-mentioned requirement will depend upon the quality of dietary protein. The higher the quality, lower the requirement and vice-versa.
Vitamins: Vitamins are organic substances present in small amount in foods. They are required for carrying out many vital functions of body and many of them are involved in the utilization of the major nutrients like proteins, fat and carbohydrates. Although they are needed in small amount, they are essential for health and well being of the body. When these vitamins were discovered on the basis of their function, and before their chemical nature was fully elucidated, they used to be designated by affixing the letter A, B, C, D or in terms of their major functions, viz. antixerophthalmic, antineuritic, antiscorbic and antirachatic vitamins. After establishing the chemical nature of these vitamins, they are now referred to by their chemical names such as retinol, thiamine, riboflavin, ascorbic acid and cholecalciferol.
Vitamins can be broadly classified as:
(i) Water-soluble vitamins
(ii) Fat-soluble vitamins
Water-soluble vitamins are:
(a) B-complex vitamins (Bp B9, Bg, Bp, etc.)
(b) Vitamins C (ascorbic acid)
Water – soluble vitamins are not accumulated in the body, but are readily excreted, whereas fat-soluble vitamins are stored in the body. For this reason excessive intake of fat-soluble vitamins can prove toxic.
Minerals and trace metals: A large number of minerals and trace metals are present in the body. Some of these form a part of body structural component and some others act as catalytic agents in many body reactions. Bones and skeleton are made up mainly of calcium, magnesium and phosphorus, and iron is a component of blood. Minerals like zinc, copper, manganese and magnesium are either structural part or activate a large number of enzyme systems. Iodine is a part of hormone thyroxin and triiodothyroxine. Sodium and potassium are important elements present in fluids within and outside the cells, and along with ions like chloride, bicarbonate and carbonate keep water and acid-base balance. On an average, man excretes daily 20-30 g of mineral salts consisting of Na, K, Mg, Ca, chloride, sulphate and phosphates, and this must be made good by an adequate intake of these mineral salts through our food.
Calcium : It is an essential element required for the formation and maintenance of skeleton and teeth, normal contraction of skeletal muscles, contraction of heart, nervous conduction and blood clotting. The richest source of calcium are milk (butter milk, skim milk and cheese) and green leafy vegetables.
Phosphorus: It is another important element next to calcium. Utilization of calcium is linked closely with that of phosphorus, since most of the calcium in the body is deposited as calcium phosphate in the bone and teeth. Phosphorus is also a component of nucleic acids. Phosphate esters play an important part in the cellular metabolism of other nutrients like carbohydrate, fat etc. The rich sources of phosphorus in our diets are cereals, pulses, nuts and oilseeds.
Iron : It is an essential element for the formation of haemoglobin of red blood corpuscles and plays an important role in the transport of oxygen. Tissues also require iron for various oxidation- reduction reactions. The major sources of iron are cereals, millets, pulses and green leafy vegetables. In addition to dietary iron, medicinal supplementation of iron is essential in certain specific conditions like anaemia and pregnancy.
Apart from these elements (mentioned above), a large number of other elements like sodium (Na), potassium (K) and magnesium (Mg) are essential as electrolyte to maintain the electrolyte balance. These elements are present in adequate amount in normal diet if taken in a balanced manner.
A large number of trace elements are required in very small amounts for a wide range of functions in the body. They are zinc (Zn), copper (Cu), selenium, cobalt, fluoride, manganese (Mn), chromium (Cr), iodine and molybdenum. Zinc is a co-factor for a number of enzymes. Copper plays an important role in iron absorption, cross-linking of connective tissues, neurotransmission and lipid metabolism. Iodine constitutes a very important part of thyroid hormone T and T4 and plays very vital role in general body metabolism. Its deficiency causes very widespread disease ‘goitre’ and mental retardation. Fluoride prevents dental caries and molybdenum is involved in uric acid metabolism.
Balanced diet: Knowledge of complex interaction of nutrients, as discussed above, helps one in choosing a balanced diet as per his/her needs and in fostering the development through better nutrition. Whatever may be the diet, it should provide adequate calories to supply the body’s energy needs. Carbohydrates with some fats are thus essential. Enough protein must be provided for tissue-building and repair. Besides all the necessary vitamins and minerals, the adequate diet should also provide sufficient water and enough fibre to promote good bowel function. A variety of foods, as described earlier, helps ensure that all the dietary needs of the body are met. Each of the major food groups should be represented adequately by one or more members:
(1) Cereal and grain products
(2) Milk and milk products
(3) Fruits and vegetables
(4) Legumes (beans, peas)
Yogic Diet ConceptTo get success in search of health and well-being, one has to establish a dietary pattern that will sustain and promote the endeavour. Such a dietary pattern may be termed as yogic diet, which may be an effective tool to move ahead in that direction. It is indeed an established fact that diet has a profound effect on both body and mind, and one cannot .attain complete physical and mental well-being without adequate diet.
In the concept of ‘yogic diet’ all food items are classified into three categories:
1. Sattvic food
2. Rajasic food
3. Tamasic food
Sattvic food: It is the purest diet and is most suitable for yoga practitioner. It nourishes the body and maintains it in a peaceful state. It also keeps calm and purifies the mind, enabling it to function at its maximum potential. The sattvic food consists of fresh, fragrant and tasty items. It includes cereals, fresh fruits and vegetables, milk and milk products, nuts, seeds and honey.
Rajasic food: It is very hot nature, spicy, bitter, sour, pungent, dry and excessively salty. Such food items are real enemy of mind-body equilibrium. They function as body stimulant and excite the passions, making the mind restless and uncontrollable. They include fish, egg, coffee, tea, meat etc.
Tamasic food: It is stale, tasteless more or less spoiled food, and containing foul odour, artificial additives, which is at all not useful to nourish either body or mind. They make the body dull, lazy, drowsy and reduce our immune power, filling the mind with dark emotions such as anger and greed. Tamasic food items include alcohol, tobacco, onions, garlic and fermented foods such as vinegar.
Thus, while practising yoga, and to maintain the state of clarity of thought, decision making, and intellectual and contemplative thinking, and to increase the body-mind vitality, one should adopt and eat sattvic food. One should ‘eat to live, not live to eat’.