Food is prime necessity of life. The food we eat is digested and assimilated in the body and used for its maintenance and growth. Food also provides energy for doing work. Man has exhibited much thought and foresight in cultivating a variety of grains, fruits, vegetables, nuts, and oil seeds; and in rearing birds and animals for use as food. Nutrition deals with the way in which the human body receives and uses all the substances or materials necessary for its growth and development and for keeping it in good condition. This begins in eating food. The food swallowed is then digested as it is passed through the stomach and small intestines. During digestion, the food is broken up into simple substances. These are absorbed into bloodstream and carried to the liver, where they are either stored or changed further or sent out to other parts of the body for use as required.
- Food: Food is defined as anything solid, liquid or semi-solid; which when ingested putting into the mouth, digested and assimilated, nourishes the body.
- Nutrients: Nutrients are defined as those chemicals substances, which are supplied by food and are needed as a source of energy and as a structural material for every cell of the body.
- Food: The edible stuff that provides us with nutrients is termed as food. Food is broadly classified as cereals, pulses, vegetables, fruits, milk, eggs, flesh food, fats and sugar.
- Nutrients: These are the constituents in food that must be supplied to the body in suitable amounts. They include proteins, fats, carbohydrates, minerals, water and vitamins.
- Nutrition status: It is defined as the extent to which a customary diet meets the body's requirement. In other words, it signifies the condition of the body after the consumption of food. The condition of health of individuals is influenced by the utilization of nutrients. It can be assessed by dietary survey, anthropometry, clinical and laboratory investigations.
NUTRITION: HISTORY AND CONCEPTS
Nutrition is the combination of processes by which the living organism receives and utilizes the materials necessary for the maintenance of its function and for the growth and renewal of its components. Nutrition is that condition, which permits the development and maintenance of the highest state of fitness in processes or activities by which the human body receives and uses all the food necessary for its growth, development, regulation and repair. It is the science of food, the nutrients and other substances therein, their action, interaction and balance in relationship to health and disease.
History of Nutrition
Nutritional discoveries from the earliest days of history have had a positive effect on our health and well-being. The word nutrition itself means “the process of nourishing or being nourished, especially the process by which a living organism assimilates food and uses it for growth and replacement of tissues.” Nutrients are substances that are essential to life, which must be supplied by food. Today, more than ever, obtaining nutritional knowledge can make a big difference in lives. Air, soil and water pollution, in addition to modern farming techniques, have depleted soil of vital minerals. The widespread use of food additives, chemicals, sugar and unhealthy fats in the diets contributes too many of the degenerative diseases of our day, such as cancer, heart disease, arthritis and osteoporosis. Here is a brief history of the science that offers the hope of improving health naturally.
The first recorded nutritional experiment is recorded in the book of Daniel in the Bible. Daniel was among the finest young men captured by the king of Babylon when the Babylonians overran Israel and was to serve in the king's court. He was to be fed from the king's table of fine foods and wine. Daniel objected and preferred his own choices, which included vegetables (pulses) and water. The chief steward was afraid for his head, but agreed to a trial. Daniel and his friends received his own diet for 10 days and then were compared to the king's men. As they appeared fitter and healthier, they were allowed to continue with their own foods, not defiling themselves with those of the king. The 20th century became the era of the Golden Age of Nutrition, when most of the discoveries of the nutrients took place. Stephen Babcock was instrumental in helping to open the age. Babcock, better known for the Babcock test for milk fat that bears his name, conceived the idea to feed dairy cattle feed from just one source, all corn plant or all wheat plant (Table 1.1).
Concept of Nutrition
Nutrition is also known as nourishment or aliment in the form of food in order to support life. The diet of an organism refers to what they eat. Many common health problems can be prevented by having a healthy diet. Dietitians are professionals who specializes human nutrition, meal planning, preparation and so on. They are trained people to provide dietary advice, for every individual, in health and disease. There are seven major classifications of nutrients, they are, carbohydrates, fiber, fats, protein, minerals, water and vitamins. These classes of nutrients are categorized as macronutrients, which are needed in relatively large amounts, and micronutrients, which are needed in smaller quantities. Macronutrients are carbohydrates, fats, fibers, water and protein; while micronutrients are vitamins and minerals.
The macronutrients provide energy, which is measured in Joules or kilocalories and written with a capital ‘C’ to distinguish them from gram calories. Carbohydrates and proteins provide 17 kJ (4 kcal) of energy per gram, while fats provide 37 kJ (9 kcal) of energy per gram. Vitamins, minerals, fiber and water do not provide energy, but are necessary for other reasons. Other nutrients include antioxidants and phytochemicals. These substances were recently discovered, which have not have been yet recognized as vitamins or contributed to health, but they are necessary for our body. Phytochemicals may act as antioxidant, but not all of them are antioxidants.
Functions of Food (Fig. 1.1)
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 the life. They also play a vital role in meeting the special needs of pregnant and lactating women and patients recovering from illness.
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, oil, butter and ghee are all good sources of energy.
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 and also supply energy.
Protective and regulatory food: Food 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.
Food has always been the central part of our community, social, cultural and religious life. It has been an expression of get-togethers. Food is served at many social events like teas, breakfasts, banquets, athletic award dinners, dances and meeting of all sorts. On all these occasions, food indirectly serves as an instrument to develop social support.
Besides other functions, food satisfies certain emotional needs also. People often find it difficult to get adjusted to unfamiliar food, although it may be nutritionally sound. Traditional habits are characterized by certain foods, which are pleasing to people of one culture and distasteful for those of another. 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.
Relationship of food to main functions: Nutrition is the process or an activity by which the human body receives and uses all the food necessary for its growth, development and functions or activities.
- Food supplies heat and energy for work and play.
- Food supplies materials for growth and repair of the body.
- Food supplies materials for regulation or control of body process and for protection of the body. People are familiar with food, but in order to understand the different types of food that are used in the body, it is necessary to know what substances or materials are present in food. These substances are called nutrients. The nutrients present in food are proteins, fats, minerals, elements and vitamins. An adequate diet should contain liberal amounts of protein rich and protective foods and it should supply all the dietary essentials in the required amounts.
Nutrition: A Basic Human Need
Nutrition is a basic human need that changes throughout the life cycle and along the health-illness continuum. The body requires food to provide energy for organ functions, body movement and work, maintain body temperature and to provide raw materials for enzymes function, growth replacement of cells and repair. Food provides nutrition for both the body and mind. Eating has evolved from being simply a necessity; is an integral component of medical treatment. The science of nutrition encompasses the study of nutrients and how they are handled by the body, as well as the impact of human behavior and environment on the process of nourishment. Nutrients alter specific substances used by the body for growth and development, activity, reproduction, lactation, heath maintenance and recovery from illness or injury. Good nutrition is a basic component of health, growth and development for maintaining health throughout the life. Proper nutrition of the nation is necessary for the nation's growth and economic development.
Nurses must understand the functions of the basic nutrients and metabolism. An understanding of the guidelines for adequate diet is essential so that, nurses can teach about nutrients and answer for the questions related to diet. Nurses must be able to assist the nutrients of the diet. They must also recognize that many divergent factors influence food intake and consider the factors when attempting to modify food intake. The factors that influence nutrient requirements are developmental considerations, i.e. age, sex, health status, culture and religion, socioeconomic status, personal preference, medications, alcohol and drugs, etc. Nurse also must be able to identify clients at risk for nutritional problems and be aware of common nutritional conditions.
The term ‘food’ refers to anything, which nourishes the body. It would obviously include solids, semi-solids and liquids, which can be consumed and which help to sustain the body to keep it healthy. The terms ‘food’ and ‘nutrition’ are sometimes used synonymously, but it is not strictly correct. Food is defined as “what one feeds on and is a composite mixture of many nutrient substances ranging from a fraction of a gram in some cases to hundreds of gram in others. The foodstuff is defined as anything, which can be used as food. Therefore, the word ‘nutrition’ is derived from the word ‘nutricus’, which means ‘to suckle at the breast’. Nutrition is defined as combination of dynamic process by which the consumed food is utilized for nourishment, structural and functional efficiency of every cell of the body.
Metabolism refers to all biochemical reactions within the body. It consists of anabolic reactions that build substances, body tissues; and catabolic reactions, those that breakdown substances. Food is ingested, digested and absorbed to produce the energy needed for these reactions. The energy requirement of an awake person at rest is called the ‘basal metabolic rate’ (BMR). BMR is the energy needed at a person's lowest level of cellular functions. Age, body size, temperature, growth, sex, nutritional status, emotional status and good intake affect individual energy requirements beyond the BMR. When energy requirements are completely met by caloric intake in food, people maintain their activity levels without weight change. If the number of calories ingested exceeds energy needs, people gain weight. When the calories ingested fail to meet energy requirements, people lose weight.
Nutrition encompasses all of the processes involved in consuming and utilizing food for energy, maintenance and growth. The processes include ingestion, digestion, absorption, metabolism and excretion. Much of the discussion throughout this chapter focuses on ingestion. Because this is the process that, the individual can control and with which, the nurse can assist the client. Basic information is presented about proper nutrition and the role of the nurse in assisting clients to meet their nutritional needs. Topics covered include, specific nutrients and their functions in the body; phytochemicals; promoting proper nutrition; factors influencing nutrition; nutritional needs during the life cycle; nutrition and health; weight management; food labeling; quality and safety; food allergies; and nutrition and the nursing process.
Physiology of Nutrition
Five processes are involved in the body's use of nutrients (Fig. 1.2):
Ingestion: Nutrition begins with ingestion, taking food into the digestive tract, generally through the mouth.
Digestion: Digestion refers to the mechanical and chemical processes that convert nutrients into a physically absorbable state. Mechanical digestion includes mastication (chewing), breaking food into fine particles and mixing it with enzymes in saliva and deglutition (swallowing food), the peristaltic waves and mucus secretions that move the food down the esophagus. Chemical digestion includes the digestive juices that changes food into the individual nutrients, which can be used by the body. Digestion begins in the stomach (except in the case of some starches for which digestion begins in the mouth) and is completed in the intestines. Peristalsis [rhythmic, coordinated, serial contractions of the smooth muscles of the gastrointestinal tract (GIT)] forces chyme (an acidic, semi-fluid paste) through the small and large intestines. Only carbohydrates, proteins and fats require chemical digestion to make the nutrients available for absorption (Fig. 1.3).
Absorption: Absorption is the process, whereby the end products of digestion (i.e. individual nutrients) pass through the epithelial membranes in the small and large intestines and into the blood or lymph systems. The nutrients are absorbed and taken to the parts of the body that need them. Most nutrients are water soluble and can be absorbed directly through the villi (finger-like projections that line the small intestine) and into the blood. Fats, which are not water soluble are absorbed first into the lymph system and eventually enter the circulatory system (Fig. 1.3).
Metabolism: The conversion of nutrients into energy by the body is called metabolism. This process is the sum total of all the biological and chemical processes in the body as they relate to the use of nutrients in every body cell. Metabolism involves two processes:
Anabolism: Anabolism is the constructive process of metabolism, wherein new molecules are synthesized and new tissues are formed, as in growth and repair. This process requires energy.
Catabolism: Catabolism is the destructive process of metabolism, wherein tissues or substances are broken into their component parts. This process releases energy. During metabolism, energy is also produced by the process of oxidation, which is the chemical process of combining nutrients with oxygen. The energy produced by the body is used in a number of ways such as electrical energy for brain and nerve activities, chemical energy for metabolism, mechanical energy for muscle contractions and thermal energy to keep the body warm. Metabolic rate is the rate of energy utilization in the body; it is expressed in units called calories. One calorie is the amount of heat required to raise the temperature of 1 g of water by (1°C). Because of the large quantity of energy released during metabolism, the energy is expressed in kilocalories (kcal), each of which is equal to 1,000 calories.
Basal metabolism is the amount of energy needed to maintain essential physiologic functions, when a person is at complete rest, i.e. the lowest level of energy expenditure. The major factor affecting basal metabolism is body composition. Lean muscle tissue has a higher metabolic rate and thus produces more energy than fat tissue. Generally, women have a lower metabolism than men, because they have a higher percentage of fat tissue; however, metabolism increases during menstruation, pregnancy and lactation. Age has also an influence, because growth periods increase metabolism. Glandular activity, especially of the thyroid gland, affects metabolism. The rate of metabolism is governed primarily by the hormones triiodothyronine (T3) and thyroxine (T4). Hypothyroid activity, a decrease in the secretion of thyroid hormones, causes a lower rate of metabolism; whereas hyperthyroid activity, an increase in the secretion of thyroid hormones, causes a higher rate of metabolism.
Excretion: Excretion is the process of eliminating or removing waste products from the body. Dietary fiber and indigestible materials, salts and other products such as bile and water are converted into feces and excreted from the body as solid waste. Other excretory organs that aid the digestive system in the elimination of wastes include the kidneys, bladder, sweat glands, skin and lungs. Most liquid waste is sent through the kidneys and bladder to be excreted as urine. Some liquid waste is removed through the sweat glands of the skin as perspiration. Gaseous waste is eliminated through the lungs.
ROLE OF NUTRITION IN MAINTAINING HEALTH
Health is defined by the World Health Organization (WHO) as the “state of complete physical, mental and social well-being and not merely the absence of disease or infirmity.” To maintain good health and nutritional status, one must eat a balanced food, which contains all the nutrients in the correct proportion.
The essential requisites of health would include the following:
- Achievement of optimal growth and development, reflecting the full expression of one's genetic potential.
- Maintenance of the structural integrity and functional efficiency of body tissues necessary for an active and productive use.
- Mental well-being.
- Ability to withstand the inevitable process of aging with minimal disability and functional impairment.
Till three decades, the role of nutrition in growth and development and tissue integrity alone was clear, but now the persuasive role the nutrition plays in the other dimensions of health is implicit. Hence, an optimal nutritional status is an indication of good health. This recent advance has brought about a large-scale change in dietary habits and practices of the population.
Facts about Basic Nutrition and Health
- The amount and kinds of food eaten affect his/her health and well-being.
- Eating the recommended servings of food ‘from the food guide pyramid’ will provide key nutrients and enable a person to meet the dietary recommendations outlined in this concept.
- Counting food servings is important to assure that adequate choices are made from the pyramid.
- New dietary guidelines are available to help a person to plan for sound nutrition.The number of calories needed per day depends upon the body's metabolic rate (BMR), which in turn, depends upon factors such as age, sex, size, muscle mass, glandular function, emotional state, climate and exercise.
- Eating well can reduce risk of various health problems and increase quality of life.
Dietary Recommendations (Fig. 1.4)
- Excess fat in the diet, particularly saturated fat, is associated with an increased risk of disease and is inversely related to optimal health.
- Modified fats and fat substitutes in the diet can have varying health consequences.
- There are some recommendations that can be followed to assure healthy amounts of fat in the diet.
- For optimal health, carbohydrates, especially complex carbohydrates, should be the principle source of calories in the diet.
- There are some recommendations that can be followed to assure healthy amounts of carbohydrate in the diet.
- Protein is the basic building block for the body, but dietary protein constitutes a relatively small amount of daily calorie intake.
- There are some recommendations that can be followed to assure healthy amounts of protein in the diet.
- Adequate vitamin intake is necessary to good health and wellness, but excessive vitamin intake is not necessary and can be harmful.
- There are some recommendations that can be followed to assure healthy amounts of vitamins in the diet.
- Adequate mineral intake is necessary for good health and wellness, but excessive mineral intake is not necessary and can be harmful.
- There are some recommendations that can be followed to assure healthy amounts of minerals in the diet.
For water and other fluids:
- Water is a critical component in the healthy diet. Beverages other than water are a part of many diets. Some beverages can have an adverse effect on good health.
- There are some recommendations that can be followed to assure healthy amounts of water and fluids in the diet.
Facts about Sound Eating Practices
- Healthy snacks can be an important part of good nutrition.
- Consistency (with variety) is a good general rule of nutrition.
- Moderation is a good general rule of nutrition.
- Careful selection of food choices is important for those who rely on fast foods as a significant part of their diet.
- There are some recommendations that can be followed concerning fast foods.
Facts about Nutrition and Physical Performance
- Carbohydrate loading and carbohydrate replacement during exercise can enhance sustained aerobic performances exceeding 1 hour in length.
- The timing may be more important than the makeup of the pre-event meal.
- High protein diets advocated for active people and athletes have been questioned by leading organizations in the areas of health, physical activity and nutrition.
- People who are interested in enhancing physical performance are especially subject to nutrition quackery.
Importance of Nutrition in 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. 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’.
Nutrition deals with the way in which the human body receives and uses all the substance or materials necessary for its growth and development and for keeping it in good condition.
This begins in eating food. The food is swallowed, then digested as it is passed through the stomach and small intestines. During digestion, the food is broken up into simple substances. These are absorbed into bloodstream and carried to the liver, where they are either stored or changed further or sent out to other parts of the body for use as required. Some are used to supply the body with heat and energy and others for the building and repair of the tissues and yet others are used to control the chemical changes taking place in the body or to protect the body from diseases, finally the waste products, which cannot be used are excreted.
Relation of Nutrition to Health (Fig. 1.5): Good nutrition is a basic component of health. The relation of nutrition to health may be seen from the following view points:
- Growth and development: Good nutrition is essential for the attainment of normal growth and development. Not only physical growth and development, but also the intellectual development; learning and behavior are affected by malnutrition. Malnutrition during pregnancy may affect the fetus resulting in stillbirth, premature birth and ‘small-for-dates’ babies. Malnutrition during early childhood delays physical and mental growth; such children are slow in passing their milestones and are slow learners in school. Good nutrition is also essential in adult life for the maintenance of optimum health and efficiency. In short, nutrition affects human health from birth till death.
- Specific deficiency: Malnutrition is directly responsible for certain specific nutritional deficiency diseases. The commonly reported ones in India are kwashiorkor, marasmus, blindness due to vitamin A deficiency, anemia, beriberi, goiter, etc. Good nutrition therefore is essential for the prevention of specific nutritional deficiency diseases and promotion of health.
- Resistance to infection: Malnutrition predisposes to infections like tuberculosis. It also influences the course and outcome of many of the clinical disorders. Infection, in turn, may aggravate malnutrition by affecting the food intake, absorption and metabolism.
- Mortality and morbidity: The indirect effects of malnutrition on the community are even more striking: a high general death rate, high-infant mortality rate, high-sickness rate and a lower expectation of life.Over-nutrition, which is another form of malnutrition, is responsible for obesity. Diabetes, hypertension, cardiovascular and renal disease, disorders of the liver and gallbladder. More recent reports suggest that diet perhaps plays an important role in certain types of gastrointestinal cancers. It is now quite well-accepted that diet and certain diseases are inter-related.
NUTRITION PROBLEMS IN INDIA
Malnutrition is widely prevalent in India. The specific nutritional problems are:
- Protein-calorie malnutrition: This is due to deficiency of calories and proteins in the diet. A large number of children are victims of kwashiorkor and marasmus in India.
- Endemic goiter: About 71 million people are estimated to be affected by endemic goiter (i.e. swelling of the thyroid gland in the neck) and other iodine deficiency disorders. This condition is due to iodine deficiency.
- Vitamin deficiencies: Deficiency of vitamin A is an important public health problem in India especially in the age group, 3–5 years.
Nutrition and Diseases
A balanced dietary intake promotes nutritional health. Genetic predisposition seems to play subsidiary role in dietary intake. Malnutrition in developing countries is essentially because of the nature of undernutrition. Inadequate dietary intake causes health problem in pregnant women, lactating mothers and growing children.
- Diet and chronic diseases: Modern epidemics of nutrition-related chronic diseases have appeared in developed countries of the world, which is attributed to the intake of ‘affluent diet’. The disease includes hypertension, coronary heart diseases, diabetes, etc. Chronic liver diseases include cirrhosis of liver, which are also prevalent in the affluent classes and are related to excessive intake of alcohol.
- Diet and cancer: Epidemiological studies carried out all over the world have established that nearly one third of all cancer types are directly related to one or the other dietary components. Diet rich in saturated fats is particularly linked to colon cancer and prostate cancer. Breast cancer and rectum cancer are also related to high-fat intake. Epidemiological studies have revealed that regular intake of fruits and vegetables high in fiber content, low in saturated fats and rich in several antioxidants, vitamins, namely retinol, carotene, vitamin C and vitamin E act as cancer anticarcinogenic agents.
- Diet and dental diseases: Diet rich in sugar content predispose to dental caries. Sugar has casual association with dental caries; the association is particularly strong during childhood years with sugars that are consumed in between meals rather than with meals. High-starch diet is not carcinogenic obviously because it contains complex sugars.
- Diet and skeletal disease: Consumption of diet, poor in calcium, may predispose to osteoporosis. Alcohol intake and smoking habits are also related to osteoporosis. Osteoporosis predisposes to fracture especially in elderly people.
- Diet and mental health: Inadequate dietary intake deficient in nutrients like iodine, nicotinic acid and iron can retard mental development or impair mental performance. Iodine deficiency can cause an extreme degree of mental impairment as seen in cretinism. Nicotinic acid deficiency can lead to dementia in extreme cases of pellagra.
- Diet and diet therapy: Dietetics is the word used to describe the practical application of the principles of nutrition to the human body in health and disease. Diet therapy is the science dealing with prescription of appropriate diet to patients, which constitutes an important component of their treatment.
NATIONAL NUTRITIONAL POLICY
The Government of India, Ministry of Health and Family Welfare developed and published the “National Health Policy” in 1983. The document gave a general exposition of the policies. The biggest omission in the draft is the lack of any discussion on comprehensive and universal health care. In contrast, the NHP 1983 had said: “India is committed to attaining the goal of ‘Health for All by the Year 2000 AD’ through the universal provision of comprehensive primary health care services”. The National Health Policy was endorsed by the Parliament of India in 1983 and updated in 2002. In brief, the draft constitutes a return to the concept of centrally-directed, institution-based health care. If allowed to be enshrined in its present form, the NHP can be used as a tool to legitimize privatization of the health sector. A further perusal of the document throws up many fundamental concerns such as the creation of an infrastructure for primary healthcare; close coordination with health-related services and activities (like nutrition, drinking water supply and sanitation); active involvement and participation of voluntary organizations; provision of essential drugs and vaccines; qualitative improvement in health and family planning services; provision of adequate training; and medical research aimed at the common health problems of the people. The draft recommends an increase in public health expenditure from the present 0.9% of GDP to 2.0% in 2010.
General objective: The general objective of the National Nutrition Policy is to improve the nutritional status of the people.
- Promote practices favorable to the improvement of the nutritional status.
- Reduce the prevalence of diseases linked to nutritional deficiencies and excesses.
- Prevent mother-to-child transmission of HIV through appropriate breastfeeding infant and young child feeding practice.
- Assure adequate treatment of malnutrition due to nutritional deficiencies and excesses.
- Provide nutritional care and support for people living with HIV/AIDS.
Expected outcomes and the link to the Millennium Development Goals (Fig. 1.7):
Goal 1: Reduce poverty: The prevalence rate of protein-energy malnutrition in children under five years of age is reduced from 45–30% for stunting, 22–15% for underweight, 4–2% for wasting.
Goal 2: Ensure primary education
- The prevalence rate of anemia is reduced from 56–37% in children and from 33–22% in women.
Goal 3: Reduce infant mortality
- Increase the proportion of women exclusively breastfeeding for the first 6 months with optimal complementary feeding up to 24 months from 74–60%.
- Reduce Vitamin A deficiency from 25% to 5% in children under five years.
Goal 4: Reduce maternal mortality
- Reduce vitamin A deficiency (night blindness) in pregnant women from 7% to less than 1%.
- Reduce the prevalence of anemia in pregnant women from 33–22%.
Goal 5: Combat HIV/AIDS and other diseases
- Nutritional support is provided to PLWA and other vulnerable people.
- Nutrition related chronic diseases are prevented.
Strategies for nutrition improvement:
- Reinforcement of the political commitment.
- Promotion of optimal infant and young child feeding.
- Scaling up of community-based nutrition programs.
- Food fortification.
- Promotion of household food security.
- Prevention and management of mal-nutrition and related diseases.
- Nutritional support to PLWHA and their families.
- Communication for behavior change.
Monitoring and evaluation: To ensure effective implementation of planned activities, monitoring and evaluation is essential in all development programs. In addition, periodic evaluations are necessary for establishing level of objective achievement. In order to follow up implementation of nutrition programs, data will be collected regularly at the health center and community level; in addition, other opportunities for nationwide surveys will be identified and utilized. Nutritional surveys and epidemiological surveillance will be conducted regularly, with appropriate indicators, to evaluate the progress and impact of nutritional interventions. Operational research will also be carried out to address specific problems identified during the implementation of nutritional activities. To prevent nutritional emergencies, nutrition unit will reinforce collaboration with all existing structures that collect and analyze bioclimatic, environmental, demographic and agricultural data for early warning and timely intervention measures against disasters that can negatively affect the nutrition.
FACTORS AFFECTING FOOD AND NUTRITION
Habits about eating are influenced by developmental considerations, gender, ethnicity and culture, beliefs about food, personal preferences, religious practices, lifestyle, economics, medication and therapy, health, alcohol consumption, advertising, and psychological factors. Although, the nutritional content of food is an important consideration when planning a diet, an individual's food preferences and habits are often a major factor affecting actual food intake (Table 1.2).
ROLE OF FOOD AND MEDICINAL VALUES (Table 1.3)
The longer that fruits or vegetables sit around waiting to be sold or eaten, the more nutrients they lose. But fruits and vegetables grown for freezing are usually frozen right after they're picked. Therefore, they have less time to lose their nutrients.
Nutritive Values of Common Foods
Food contains nutrients in different proportions and with different organoleptic properties. Hormonal substances, enzymatic substances and antioxidants are present in various proportions in addition to micro and macronutrients (Fig. 1.8).
- Cereals: They are rich in carbohydrate, low in protein (6–12%), low in fat, poor in iron and calcium. Rice, barely, ragi, millets and wheat are some of the examples of cereals. Insulin stimulants are present in ragi and millets former is rich in calcium, latter is a source of fiber. Except yellow maize and sorghum, cereals have previtamin A and ascorbic acid. Wheat has acarbose, a chemical helpful to maintain normal blood sugar level. Richest source of iron are bajra and samai (panicum miliare). 100 g of staple food or cereals yield 346 kcal of energy.
- Pulses and legumes: They are generally called protein foods. They contain 22% protein-soluble and insoluble fiber. They are rich in potassium and vitamin B, deficit in methionine, but rich in lysine. More than 40% of protein is present in soybean. It is the richest source of protein among the plant foods. Calorific value of pulses and legumes are ranging from 315–372 kcal for every 100 g. But green peas and soybean provide 93 and 432 kcal, respectively.
- Green leafy vegetables: They are low-calorie foods, having 90% moisture, high-fiber, low-protein, rich vitamins and minerals particularly beta-carotene and calcium. In general, greens do not have protein in sufficient amount, but agathi greens contain 8% protein. Low-cost nutritious food like curry leaves have 800 mg calcium for every 100 g. Araikeerai is richest source of iron. Familiar greens like Amaranthus gangeticus are good for normal cardiac function, as it provides potassium. Amaranthus tristis and A. viridis are excellent source of iron and ascorbic acid, respectively. Commonly used green leafy vegetables are coriander leaves, drumstick leaves, mint, amaranth, celery, spinach and curry leaves.
- Other vegetables: They are known as low-caloric foods, which contain potassium, soluble fiber, vitamin B and ascorbic acid. Some types of vegetable are good source of calcium, e.g. sundakkai and field beans. Folic acid present in lady's finger and chow chow helps in malnutrition of red blood cell (RBC). Choline of pumpkin and cauliflower is vital and regulates fat metabolism.
- Roots and tubers: They are poor source of protein, but good source of carbohydrate. Beta-carotene in carrot and yam, ascorbic acid in potato, magnesium in pink radish, and phosphorus in colocasia are particularly helpful to meet normal requirements of recommended dietary allowances for an individual.
Healthy Substances of Food
- Tomato: It has lycopene, which is anticancer carotenoid.
- Bitter gourd: It is an insulin stimulant.
- Cruciferous vegetables: Brussels sprouts, broccoli and which has indole, resist cancer of womb.
- Cucumber: It is diuretic and has arginine.
- Green tea: It contains catechins, an antioxidant.
- Fruits: Fruits are roughage, provide bulk to the stools. Most of the fruits are good sources of vitamins and minerals. Ascorbic acid in alma is richer than fruits such as orange, lime and grapes. 100 g of Indian gooseberry yields 600 mg of vitamin C. Beta-carotene, a precursor of vitamin A, found in mango and papaya helps to maintain good vision because of an action similar to pepsin. Papain relieves the symptoms of episiotomy (surgical incision of vulva during delivery). Watermelon is a very meager energy yielder, whereas dried fruits provide high calories. A report by National Academy of Sciences found that resveratrol, a chemical known to be highly concentrated in grapes skin, acts like estrogen, a hormone known to protect against heart diseases.
- Nuts and oil seeds: They are rich in saturated fats; contain tocopherol, thiamine and niacin. Almond, cashew nut, groundnut, walnut, sesame seed, linseed are some sources of nuts and oil seeds. Groundnuts contain monounsaturated fatty acid, 25% protein and 40% fat. Nutritious ball made from groundnut and jaggery is a healthy food for children. Coconut meals raises hemoglobin content, as it provides approximately 70 mg iron. Most of the nuts and oil seeds are energy yielder and rich in phosphorus. Short-and medium-chain fatty acid of coconut oil is good for infant-intestine.
- Eggs: They are good mixture of all nutrients except carbohydrate and fiber; supplies essential amino acids and termed as good quality proteins. Raw egg white contains antinutritional factor avidin, which binds with biotin and makes it unavailable. Ovalbumin, ovomucoid, flavoprotien are egg white proteins. One egg yolk contains 200 g cholesterol and proteins such as lipovitellin and phosvitin. 13% fat, 170 kcal energy, 2 mg iron, 60 mg calcium, 220 mg phosphorus can be obtained from 100 g of egg. Cooked egg is better than raw egg.
- Meat poultry and fish: Beef meat is richest source of iron among meat products. Protein in the meat and meat products are superior compared to vegetable proteins. Essential amino acids and biological value are responsible to upgrade the quality. Protein value of mutton is less than that of chicken, but fat percentage is higher than fish and chicken. They all are moderate source of phosphorus. Common fish varieties rohu and katla have 1.4% and 2.4% of fat, respectively. Cat fish is free from fat. Fatty fish are hilsa, tapsee and dried chela. Omega fatty acid content of fish is helpful in preventing cardiac diseases. Consumption of cod-liver oil protects eyes from night blindness.
- Milk and milk products: Milk is ideal food from infant to aged. Skimmed milk, cheese, tinned milk powder, khoa and supplementary foods are made from milk. Cow milk, buffalo milk and processed milk are widely consumed. Protein content of cow milk is higher than human milk, but buffalo milk is rich in fat. High protein and calcium content among milk products is in skimmed milk powder. This group of foods have sufficient phosphorus, thiamine, niacin, but deficit in iron and vitamins. Energy value of 100 g cow milk, buffalo milk, goat milk, human milk is 67, 117, 72 and 65 calories, respectively.
CLASSIFICATIONS OF FOOD
Food does much more that satisfy your appetite. It provides nutrients that the body uses for growth and health. There are five types of nutrients that fall into two broad categories: macronutrients and micronutrients. Macronutrients, which are required in large amounts include carbohydrates, proteins and fats. In contrast, micronutrients are required in small amounts that include vitamins and minerals. A sixth category includes water, which is essential to life.
Classification by Origin
- Food of animal origin
- Food of vegetable origin
Classification by Chemical Composition
Classification by Predominant Function
- Body building foods, e.g. milk, meat, poultry, fish, eggs, pulses, ground nuts, etc
- Energy giving foods, e.g. cereals, sugars, roots and tubers, fats and oil
- Protective foods, e.g. vegetables, fruits, milk.
Classification by Nutritive Value
- Cereals and millets
- Pulses (legumes)
- Nuts and oil seeds
- Animal foods
- Fats and oil
- Sugar and jaggery
- Condiments and spices
- Miscellaneous foods.
Since, the food is varying in their contents of various nutrients, they have been broadly grouped under three categories from the nutritional point of view (Fig. 1.9).
- Energy yielding foods.
- Body building foods.
- Protective foods.
These are briefly discussed below:
Energy yielding foods: Food rich in carbohydrates and fats are called energy yielding foods. Cereals, roots and tubers, dried fruits, sugars and fats are included in this group. Cereals contain, in addition, fair amounts of proteins, minerals and certain vitamins and form the important sources of the above nutrients.
Body building foods: Food rich in proteins are called body building foods. Milk, meat, fish, eggs, pulses, oil seeds and nuts and low-fat oil seed flours are included in the group of body building foods.
Protective foods: Food rich in protein, vitamins and minerals are termed protective foods. Milk, eggs, liver, green leafy vegetables and fruits are included in this group. Protective foods are broadly classified into two groups:
- Food rich in vitamins, minerals and proteins of high biological value, e.g. milk, eggs and liver.
- Foods rich in certain vitamins and minerals only, e.g. green leafy vegetables and fruits.
Five Food Group Plans
The nutritional expert group of Indian Council of Medical Research, India suggested a five food group plan and the nutrients supplied by each food group are given in Table 1.4.
Basic Seven Food Groups
The seven food group plan was developed by US department of agriculture in 1943. The seven groups with their nutrient contribution are given in Table 1.5.
ELEMENTS OF NUTRIENTS: MACRO AND MICRO
Review of nutrients: Macro and Micro nutrients: Nutrients which are needed by the body for good nutritional status are provided by the food. An individual nutritional status is dependent on the provision of sufficient nutrients and the good utilization of these nutrients. Status of nutrition may be caused by eating food, i.e. inadequate in amount and kind, or it may be caused by failure in digestion and utilization of these nutrients. The nutrients present in food fall into three major categories: proximate, vitamins and minerals. The proximate usually referred to as proximate principles include only those nutrients that yield energy on oxidation, i.e. carbohydrates, proteins and fats. Nutrients are organic and inorganic complexes contained in food.
Macro and Micronutrients: Macro nutrients are carbohydrate, protein and fats which are often called “proximate principles” because they form a main bulk of the food.
These are vitamins and minerals. They are called micronutrients because they are required in small amounts. A vitamin is an organic compound that cannot be manufactured by the body and is needed in small quantities to catalyze metabolic processes. When these vitamins are lacking in the diet, metabolic deficits results. Minerals are found in organic compounds and inorganic compounds as free ions. On oxidation, minerals leave an ash, which can be acid or alkaline.
Carbohydrates: Carbohydrates are the chief, cheapest and main source of energy. Carbohydrate normally should provide 50–60% of total caloric requirements. All the carbohydrates contain carbon, hydrogen and oxygen. All the carbohydrates are changed in the body to simple form called glucose (Fig. 1.10).
Carbohydrate can be classified into three categories:
- Monosaccharide—Glucose, fructose, galactose
- Disaccharides—Maltose, lactose, sucrose
- Polysaccharides—Starch, glycogen
Food sources of carbohydrates include sugars, cereal grains, legumes and dried fruits, which are the richest sources of carbohydrates. White sugar is almost pure carbohydrate but cereal grains, legumes and dried fruits may vary in their carbohydrate content. One gram of carbohydrate gives 4 calories of energy on burning. Intake of carbohydrate is ordinarily greater than that of fat for energy. Carbohydrates are also useful in the detoxication of ammonia. The main functions of carbohydrates have a variety of functions in the animal and human body. They supply energy for body functions and for doing work. They are essential for the oxidation of fats. They exert a sparing action on proteins and they add flavor to the diet. Diabetes mellitus is a chronic disease in which blood glucose level is raised above 180 mg per 100 mL blood and glucose is excreted in urine. This disease is primarily due to the insufficient production of hormone-insulin by the beta cells of the islets of Langerhans of the pancreas.
Proteins: The name “protein” was suggested by Mulder in 1838 to the complex organic nitrogenous substances found in animal and plant tissues. Protein constitute about one-fifth (20%) of animal body on the fresh weight basis. They are essential for life processes. They play an important role in many biochemical and biophysical processes in the body.
Classification of proteins:
- Simple proteins: These include albumins, globulins, glutelins, prolamins, fibrous proteins, histones and protamins.
- Conjugated proteins: These include nucleoprotein, glycoprotein, phosphoproteins, hemoglobin and lecithoproteins.
- Derived proteins: These include proteins, metaproteins, coagulated proteins, peptones and peptides.The main functions of proteins are to replace the daily loss of body protein, to provide amino acids for the formation of tissue proteins during growth, and to provide the amino acids necessary for the formation of enzymes, blood, proteins and certain hormones of protein nature, and to provide amino acids for growth of fetus in pregnancy and for the production of milk proteins during lactation. Disease due to the deficiencies of protein and calories occur commonly among weaned infants and preschool children in India and other developing countries. They may be classified into three group–kwashiorkor, nutritional marasmus and marasmic- kwashiorkor.
- Lipids: The term “lipids “is applied to a group of naturally occurring substances characterized by their insolubility in water, greasy feel and solubility in some organic solvents. Fats are solid at 20°C, they are called “oils” if they are liquid at that temperature. They are classified as 1. Simple lipids e.g. triglycerides 2. Compound lipids, e.g. phospholipids 3. Derived lipids, e.g. cholesterol.
Sources of fats may be classified as:
- Animal fats (fat of meat and fish), ghee, butter, milk and eggs.
- Other sources from cereals, pulses, nuts and vegetables.
The fats are high energy foods, providing as much as 9 kcal for every gram. Fat in the body support viscera such as heart, kidney and intestine, and fat beneath the skin provides insulation against cold. Cholesterol is essential as a component of membranes and nervous tissue and is a precursor for the synthesis of steroid hormones and bile acid, A diet, rich in fat can pose a threat to human health encouraging obesity, phrenoderma, coronary heart disease, and cancer and skin lesions of kwashiorkor. When the cholesterol level is over 250 mg/100 mL, the incidence of atherosclerosis and coronary heart disease is high.
Vitamins: Vitamins may be defined as organic compounds occurring in small quantities in the different natural foods and necessary for the growth and maintenance of good health in human being and certain experimental animals. Vitamins may be classified into two groups (a) Fat soluble vitamins, e.g. vitamin A, D, E, and K. (b) Water soluble vitamins, e.g. vitamins of the B group and vitamin C.
- Vitamin A: Vitamin A occurs only in foods of animal origin. Vitamin A activity is also possessed by carotenoids found in plants. Hence, carotenoids are called provitamin A. Vitamin A is not synthesized in the body and must by supplied by food supplements. One of the best defined roles of vitamin A is its requirements for normal vision. Vitamin A is necessary for the health of the epithelial cells. Vitamin A deficiency is one of the main causes of blindness in India. The signs of vitamin A deficiency are predominantly ocular. They include night blindness, conjunctival xerosis, Bitot's spots corned xerosis and keratomalacia. The term “xerophthalmia” (dry eye) comprises all the ocular manifestations of vitamin A deficiency ranging from night blindness to keratomalacia.
- Vitamin D: Although, deformed bone conditions had been known countries, it was not until 1922 that the cause of rickets was discovered. Many investigations noted that a poor environment, consisting of poor hygiene, lack of sunshine and exercise and often city dwelling was associated with the incidence of rickets. In 1824, cod liver oil was recommended as a remedy for rickets. Vitamin D helps in absorption of calcium and phosphorous and makes them more available for the development of bones. Rickets is the disease caused due to deficiency of vitamin D. The disease is characterized by deformities of the bones like knock knees and bow legs which may last throughout, fish liver oils provides the most potent sources of this vitamin. Also ultraviolet rays of sunlight help in the synthesis of vitamin D in skin.
- Vitamin E: Vitamin E is the generic name for a group of closely related and naturally occurring fat soluble compounds, the tocopherols, of these alpha–tocopherol is biologically the most potent. Vitamin E is widely distributed in foods. The usual plasma level of vitamin E in adult is between 0.8 and 1.4 mg per 100 mL. A deficiency of vitamin E in various species of animals results in reproductive failure, macrocytic anemia and shorter lifespan of red blood cells. Recently, the cytotoxic effect of vitamin E on human lymphocytes, in vitro, at high concentrations has been reported.
- Vitamin K: Vitamin K is necessary for the synthesis of prothrombin, an enzyme synthesized by the liver; prothrombin is required for normal clotting of blood. Vitamin K is found in plants. Good sources are cauliflower, spinach and soyabean. In contrast, fruits, cereals and animal products contain little vitamin ‘K’. It is also synthesized in the intestinal tract by the bacteria.In the newborn babies, intestinal bacteria are not sufficiently developed for the synthesis for vitamin ‘K’. Thus some infants, especially those who are immature, show susceptibility to hemorrhage. Vitamin K is given to infants immediately after birth especially to those who show hemorrhage tendency.
- Thiamine: Thiamine (vitamin B1) is a water soluble vitamin. It is essential for the utilization of carbohydrates. In thiamine deficiency, there is accumulation of pyruvic and lactic acids in the tissues and body fluids. Thiamine occurs in all natural foods, although small amounts. Important sources are whole grain cereals, wheat gram, yeast, pulses, oilseeds and nuts especially groundnut, meat, fish eggs, vegetables and fruits contain smaller amounts. Thiamine functions in the release of energy from the metabolism of carbohydrate. As a result, thiamine is related to the maintenance of a normal appetite, normal muscle tone in the gastrointestinal tract and healthy nervous system. More advanced deficiencies result in the disease beriberi. There are two types of beriberi. The dry form is characterized by severe muscular wasting, loss of sensation in the skin, loss of weight and paralysis of lower limbs. The wet form produces marked edema which usually starts from lower limbs and develops upward. When it reaches the trunk, involves heart and the result is heart failure.
- Riboflavin: Riboflavin (Vitamin B2) is a member of B group vitamins. It has fundamental role in cellular oxidation. It is a cofactor in a number of enzymes involved in energy metabolism. Its richest natural sources are milk, eggs, liver, kidney and green leafy vegetables. Meat and fish contain small amounts. There are no real body stores of riboflavin. Low dietary intake of riboflavin may result in fissures at the angle of the mouth, accompanied by the yellow cast. The tongue may exhibit glossitis, turning to purplish-red in color, accompanied by a painful burning sensation.
- Nicotinic acid (Niacin): Nicotinic acid contains a pyridine nucleus. It is essential for the metabolism of carbohydrate, fat and protein. Nicotinic acid is essential for the normal functioning of the skin, intestinal tract and the nervous system. Food rich in niacin or tryptophan are liver, kidney, meat, poultry, fish, legumes and groundnut. Milk is a poor source of niacin. Nicotinic acid deficiency causes the disease “pellagra” in human beings. This disease is characterized by three D's—dermatitis, diarrhea and dementia. The dermatitis and diarrhea are two distributions and occurs in the hands, feet and neck.
- Pyridoxine (B6): Pyridoxine (vitamin B6) exists in three forms, pyridoxine, pyridoxal and pyrioxamine. It plays an important role in the metabolism of amino acids, fats and carbohydrates. Rice dietary; sources are dried yeast rice polishing, wheat gram and liver. Pyridoxine is essential for maintaining the nerves in normal condition. Pyridoxal phosphate acts as coenzyme in the metabolism of amino acids. Effects of deficiency in human adults are seborrhea like lesion developed around the eyes, nose and mouth within 2–3 weeks. In infants, deficiency seen as nervous irritability and convulsive seizures.
- Pantothenic acid: Pantothenic acid is one of the vitamins of the vitamins B complex, which can prevent or cure a specific type of dermatitis (chick pellagra) in chicks fed on vitamin B2 deficient. Pantothenic acid in the form of coenzyme A takes part in the metabolism of carbohydrates and fats. It is essential for the oxidation of pyruvic acid. Burning feet syndrome was observed in prisoners of war during World War II in Japan, and Burma. This syndrome was associated with neurological and mental disturbances. Gopalan (1946) found that burning feet syndrome observed in Indian subjects responded to treatment with calcium pantothenate (20–40 mg).
- Folic acid: Folic acid was known under different names from 1933 by its curative effects in deficiency states in man and in different experimental animals. It is essential for the maturation of red blood cells. It acts as a coenzyme in the synthesis of methionine and of purine and pyrimidine rings. Foods such as liver, meat, dairy products, eggs, milk, fruits and cereals are as good dietary sources as leafy vegetables. Overcooking destroys much of folic acid and thus contributes to folate deficiency in man. Nutritional megaloblastic anemia in adults, the classical studies of Wills (1931) in India showed that the megaloblastic anemia is prevalent in pregnant women of the low income groups substituting on poor vegetarian diets. Megaloblastic anemia has been reported to occur among malnourished children in the developing countries.
- Vitamin B12 (cyanocobalamine): Cyanocobalamine was found effective in curing pernicious anemia when administered intramuscularly; in small quantities (5–10 mg); for the absorption of vitamin B12 from the intestines; a factor called “Intrinsic factor” (IF) secreted by the stomach is essential to store vitamin B12 in fair amount in the liver. Vitamin B12 promotes the maturation of red blood cells. It acts on the narrow elements and is involved in the formation of white blood cells and blood platelets. It cures the neurological symptoms of pernicious anemia. It acts as a coenzyme in the synthesis of methione. Vitamin B12 deficiency causes the disease “pernicious anemia”.
- Ascorbic acid: Ascorbic acid is essential for the production of collagenous or intracellular material which holds the cell in proper relation to each other. It is also important for healthy development of teeth, bones and cartilage and connective tissues. It is an important factor in the healing of wounds and in the ability to withstand stresses of injury and infection. A well-balanced diet for school children and adults should contain 30–50 mg of vitamin C per day. The major functions of vitamin C is oxidation of tyrosine, reduction of ferric iron to ferrous iron in gastrointestinal tract so that iron is more readily absorbed, and conversion of folic acid into its active form folinic acid. Scurvy is the drastic consequence of vitamin C deficiency. The principle symptoms of scurvy are restlessness, loss of appetite generally soreness to touch, sore mouth, bleeding gums and loosening of the health.
There are a number of minerals or inorganic elements that play an important role in nutrition. Mineral elements are present in organic compounds, such as hemoglobin, phospholipids; and in thyroxine inorganic compounds, such as in sodium chloride and calcium phosphate; and as free ions. They enter the structure of every cell of the body. Hard skeletal structures contain the greater proportions of some elements, such as calcium, phosphorous, and magnesium, while soft tissues contain relatively higher proportions of potassium.
Mineral elements enter into numerous regulatory activities of the body. The contraction of muscles, the normal response of nerves to stimulation, the control of water balance, the maintenance of acid base equilibrium and the water balance of the food-stuffs are common functions. Sodium, potassium, calcium, phosphorus and chloride are the essential constituents of body fluids. Calcium, magnesium, phosphorus and others are bone constituents. Iron, copper and cobalt function in an intendated manner together with protein, vitamin B12 and other nutrients for the synthesis of hemoglobin and red blood cells.
- Body contains calcium in greater amount than other minerals.
- About 2%of the body weight of an adult is due to calcium, out of which about 99% is contained in bones and teeth.
- Calcium is the most important factor in building skeleton and teeth, is more important during growing years.
- Normal behavior of heart, nervous system and blood clotting process, etc. depend on the presence of calcium.
- Human body at different levels of intake has suggested the desirability of a daily intake of about 0.4–0.6 g of calcium by an adult, in the case of growing children, pregnant and lactating mothers the requirement is 1.0 g per day.
- Milk and milk products are the richest sources of calcium. Green leafy vegetables, such as spinach, amaranth are rich in calcium, but at the same time they are oxalate-rich foods.
- Phosphorus takes a second place in regard to the total amount of minerals present in the body and constitutes about one-fourth of all body minerals.
- About 80% of the phosphorus is found in bones combined with calcium and the rest is found in bones combined with calcium and the rest is found in soft tissues and body fluids.
- Phosphorus plays an important role in the formation of teeth and bones, maintenance of acid base balance of the blood, and supplying energy to the muscles for contraction.
- Phosphorus is found in good amount in the foods which are rich in protein and calcium. Thus milk, cheese, egg yolk, meat, fish are good source of phosphorus.
- Deficiency of calcium and phosphorous causes rickets in children which is generally contributed by the lack of vitamin D. Osteomalacia, the adult rickets, may also be due to calcium deficiency, but usually, the situation is complicated by the deficiency of phosphorus and vitamin D as well as other factors.
- Amount of iron in the adult body is about 3–5 g; of which 70% is in circulating hemoglobin, 4% in the myoglobin of the muscles and 25% in the stores held in liver, bone marrow, spleen and kidneys.
- Iron is essential for the oxidation of the body. Hemoglobin combines with oxygen in the lungs to form oxyhemoglobin and is carried to the tissues by blood circulation.
- Iron containing oxygen in the muscles makes the oxidation of carbohydrate, fat and protein possible within the intact cell.
- Iron is stored chiefly in the liver, spleen and bone-marrow. The amount is variable, ranging from 1–2 g.
- Recommended allowances based on the availability and utilization of iron, it is recommended that 20–30 mgs of iron per day is sufficient for an adult. The requirements increases in special conditions like pregnancy.
- Nutritional anemias are due to the deficiency of iron, folic acid, etc.
- Liver is an excellent source of iron. Other meat products and egg yolk also have generous amount of this mineral.
- Primary function of thyroxine is to influence the rate of oxidation in the cells of the body. Thyroxine also helps in normal growth and development in the youngs of all the species.
- Sources of iodine vary widely under different soil and fertilizer conditions. Marine or deep sea fish and shell fish are high in iodine content. The leaves and flowers of plants have higher concentration of iodine than roots.
- The recommended daily allowances of iodine have been reported to be about 100–150 mg.
- Prolonged deficiency of iodine not only develops goiter but also causes sterility in many cases. Development of goiter or enlargement of thyroid gland, pregnancy need special requirement of iodine.
- Fluorine is found primarily is the bones and teeth. Small amount fluorine brings about striking reduction in tooth decay because this mineral makes tooth enamel more resistant to the action of acid.
- Dental caries is reduced due to more resistance to the action of acid; water is flourinated at the rate of 1 part per million.
- Sources of fluorine—food as well as water by fluorination of the water at the rate of 1 part per million.
- The recommended level of fluorides in drinking water in this country is accepted as 0.5–0.8 mg per liter.
- Fluorine is often called a two-edged sword. Prolonged ingestion of fluorides through drinking water, in excess of the daily requirement, is associated with dental and skeletal fluorosis, and inadequate intake with dental caries.
- The adult human body contains about 100 g of sodium ion. It is distributed entirely in the extracellular fluid (plasma, tissue fluid and lymph) of the body.
- The main functions of sodium is regulation of acid–base balance of the body, regulation of osmotic pressure of plasma or tissue fluids; and sodium play a special role in originating and maintaining heartbeat.
- Low sodium diets are prescribed for patients suffering from high blood pressure.
- The adult human body contains about 250 g potassium which is present almost in the cells of different tissues, muscle, etc.
- The functions of potassium is regulation of pH of the cell contents, regulation of the osmotic pressure of cell contents; and potassium ion increases the relaxation of heart muscle which is antagonized by cell contents calcium.
- Potassium deficiency causes weakness and muscular paralysis. In animals, hyper-trophy of the heart has been observed.
- Consumption of excessive amounts of potassium causes muscular weakness and apathy-symptoms, similar to those of potassium deficiency.
- Magnesium is a constituent of bones and is present in all body cells.
- Human adult body contains about 25 g of magnesium of which about half is found in the skeleton.
- It appears that magnesium is essential for the normal metabolism of calcium and potassium.
- Magnesium deficiency may occur in chronic alcoholic, cirrhosis of liver, toxemias of pregnancy, protein–energy malnutrition and malabsorption syndrome.
- The requirements are estimated to be about 200–300 mg/day for adults.
- The healthy human adult body contains about 100–150 mg of copper. Copper is present in the blood in the form of copper protein complex hemocuprin in red blood cells and ceruloplasmin in plasma.
- Anemia produced in infants, fed exclusively on milk, can be cured only by giving copper salts along with iron. The estimated average daily intakes in adult diet range from 2–3 mg.
- The high intake of copper in Indian diets may due to contamination of copper from brass vessels used in cooking.
- Zinc is active in the metabolism of glucides and proteins, required for the synthesis of insulin by the pancreas and for the immunity function.
- Zinc is present in small amount in all tissues. Plasma zinc level is about 96 mg per 100 mC for healthy adults and 89 mg per 100 mC for healthy children.
- The average adult body contains 1.4–2.3 g of zinc. Zinc deficiency in the diet has been reported to the cause of anemia, growth retardation (dwarfism) and delayed genital maturation in children.
- Zinc is a constituent of insulin—the hormone present in the islets of Langerhans of pancreas.
- Cobalt occurs in small amounts in all tissues, highest concentration occurring in liver and kidneys. Most of the cobalt is present in vitamin B12.
- It is suggested that cobalt may be necessary for the first stage of hormone production. Cobalt may interact with iodine and affect its utilization.
- The chromium content of an adult human body is estimated to be 6 mg. Most adult tissues contain 0.02–0.4 ppm of chromium on dry basis. The blood contains about 0.009–0.055 ppm.
- Chromium plays an important role in carbohydrate, lipid and protein metabolism.
- Chromium deficiency is characterized by impaired growth and disturbances in glucose, lipid and protein metabolism.
- Selenium administration to children with kwashiorkor resulted in significant weight increase.
- Studies indicate that human selenium deficiency may occur in protein– energy malnutrition.
- Selenium deficiency especially when combined with vitamin E deficiency, reduces production.
CALORIE AND BASAL METABOLIC RATE
The scientific definition of a calorie is a unit of energy or heat, in particular. One calorie is the amount of heat that increases the temperature of 1 kg of water by 1°C. Any food may contain one or more nutrients, but carbohydrates, fats and protein are the nutrients which gives calories to the body. The caloric value of these nutrients and of any common food have been determined by burning a known weight of the nutrient or food in an atmosphere of oxygen, in what is known as a bomb calorimeter. The caloric values of the nutrients are given in Table 1.6.
The following examples of calorie intake are based on US Department of Agriculture (USDA) guidelines: A person's daily calorie intake should be based on age, gender and physical activity level.
Men generally need more calories than women and active people need more calories than sedentary (inactive) people.
- Children aged between 2 and 8: 1,000–1,400.
- Active women aged between 14 and 30: 2,400.
- Sedentary women aged between 14 and 30: 1,800–2,000.
- Active men aged between 14 and 30: 2,800–3,000.
- Sedentary men aged between 14 and 30: 2,000–2,600.
- Active men and women above 30: 2,200–3,000.
- Sedentary men and women 30: 1,800–2,200.
Body Mass Index and Basal Metabolic Rate of Body
Body mass index (Quetelet's Index): The body mass index is used as a reference standard for assessing the prevalence of obesity in the community.
Body mass index = weight in kg/height in meters. Ideal body mass index:
- Ideal body mass index for Indian women: 19–24.
- Ideal body mass Index for indian men: 20–26.
Once the body mass index exceeds the normal limit, the person can be termed as overweight or obese.
Basal metabolic rate: The Basal metabolic rate is the minimum number of calories needed to maintain vital functions, such as breathing and keeping the heart beating. It is the energy expenditure necessary to maintain basic physiologic conditions such as respiration, cardiac contraction, conduction of nerve impulses, metabolic activity such as synthesis of macromolecules under standard conditions, reabsorption of kidney, iron transport across impulse. These functions occur continuously without one's own conscious or awareness. Basal metabolic needs are surprisingly large, a person whose total energy expenditure amounts to 2,000 calories/day spends as much as 1,200–1,400 calories to support usual metabolism.
- Basal metabolism is the minimum amount of energy needed by the body for the maintenance of life when the person is at post absorptive state, physical and emotional rest.
- Basal metabolic rate is a measure of the energy required by the activities of resting tissue which can be measured directly from the heat produced (using a respiration calorimeter and metabolic chamber) or indirectly from O2 intake and CO2 expenditure when the subject is at rest.
- Basal metabolic rate values are expressed as kcal or kJ per square meter of body surface per hour.
- In adults, basal metabolic rate for healthy males 40 kcal/h (168 KJ) per hour and in healthy females is 37 kcal/h(155 KJ).
Factors Affecting Basal Metabolic Rate
There are many factors, which affect the basal metabolic rate, the most common factors are (Table 1.7):
NURSE'S ROLE IN FOOD AND NUTRITION (FIG. 1.11)
Why is nutrition so important and what is the nurse's role in nutrition? Nutrition is essential because it's required for growth, healing and all body functions. The nurse's role in nutrition is to educate patients about good nutrition to promote health. In this research paper, we will be discussing the nurse's role in nutrition and strategies that can be implemented in the hospital, nursing home and community.
- Hospital: In a hospital setting, physicians will issue orders for a diet type just as they write orders for medications or treatments. Knowledge of nutrition plays a role for the nurse because she must be aware of the significance of each diet. A nurse must know the component of each diet because if a patient asks for a carton of milk for a clear-liquid diet, this is not permitted. A full-liquid diet permits dairy products, however, knowing low-sodium and low-sugar choices for cardiac and diabetic patients, respectively, is also important for ensuring that the patient does not eat food that would adversely affect him. Nutrition is believed to be a key issue for healthcare professionals in hospital settings, yet the management of nutritional problems is often poor.According to O'Regan (2009), “nutrition should be viewed as an integral and central component of patient care irrespective of the patient's physical diagnosis, condition, age or psychological status”. A failure to address the issue of malnutrition is a failure of the duty of nurses to protect the health of patients. In hospital environments, nurses are obliged to make observations about physical status, food intake, weight changes and response to therapy.
- Nursing home: The nurse's role in nutrition can affect the nutritional status of residents of a nursing home. Many nutritional issues arise in residents of a nursing home. Nurses play a major role in ensuring that the resident's nutritional needs are met. Documenting changes in weight loss, decreased appetite, oral health, and physical activity are examples of the important role that they play in their evaluation of the nutritional status of their patients. Morley and Silver (1995) raise the important fact that, “Without input from staff, the physician is not likely to be successful in evaluation and treatment”. It is important that we include nutrition as we evaluate our patients and plan their care. Authors, Morley and Silver (1995), stressed “Careful attention to the nutrition of nursing home residents is both a clinical and a quality-of-life issue”.
- Preventive care: Nurses are constantly engaged in teaching moments, particularly for preventive care. For example, if a patient has a family history of high blood pressure, a nurse may wish to teach him/her about healthy choices, such as a low-sodium diet, that can slow the onset of high blood pressure. Nurses also can help to review a patient's current diet to pinpoint areas where he/she can make healthier food selections.
- Nutrition knowledge and medications: Nutrition plays a further role in nursing when it comes to reviewing a patient's medication list. For example, patients who are on therapies to prevent blood clotting may need to avoid leafy, green vegetables and other vitamin K containing foods. This is because vitamin K can decrease the beneficial effects of blood thinners. Some food such as grapefruits and food containing tyramine, an amino acid or building block of protein responsible for regulating blood pressure, can interfere with medication therapies. Examples of tyramine-containing food include aged cheeses, soy sauce and draft beer. When educating a patient on a new medication, nutrition must be a key component discussed to ensure safe drug administration.
- Community: People in the community that was studied show their lack of knowledge when they make poor food choices. The nurse's role in nutrition is to educate patients on how to improve eating habits to promote good health. To effectively manage and prevent malnutrition in either setting, it is important to recognize the barriers to nutritional care for patients. According to Dupertuis as cited by O'Regan (2009), inadequate nutrition can lead to an increase in hospitalization and mortality. As nurses provide nutritional care for patients in each of these settings, they should be educated on the importance of nutrition and the healing process to assist patients in avoiding a failure to thrive diagnosis.
The importance of food in the care and treatment of hospital patients has been championed by the nursing profession for many years. Nonetheless it is still a neglected branch of nursing. The Salmon Report (1966) on senior nursing staff structure is widely believed to have diminished the importance of nutritional care as a key nursing role, so much so that the UKCC (now NMC) wrote to all registered nurses reminding them of their responsibilities in this area. As nurses and nurse practitioners become more involved with nutritional interventions, the health of patients will improve. Starting in the community, with meaningful nutrition interventions, patient outcomes and health can be changed, for much of the result depends on nursing's focus. In the busy lives of nurses, patients often get looked at as a disease; while that is not a nursing concept, it is often a fact of life. Instead if we see clients as the complex individuals that they are, the advantage of early nutrition intervention becomes obvious.
Proper nutrition is important for staying healthy and is particularly vital for the elderly. The nutritional state of a patient often affects patient outcomes during illness and recovery. The nurse is the logical person to provide nutritional information because nurses are the primary interface between the patient and the healthcare system. Nursing plays a key role in nutrition education because nutrition is a part of patient outcomes. The healing of the body can take place only when the nutrients, that provide the building blocks for repair, are present. The nurse as a nutrition educator is a vital role in the overall healthcare system. Prehospital nursing has the opportunity to provide nutrition education that can help to preserve the health of all populations and particularly of older adults, much has been written about eating dysfunction in the geriatric population. In the role of nutrition educator, nurses can work to prevent frailty in the older population.
- Define nutrition; explain briefly about the history of nutrition.
- Discuss the role and importance nutrition in maintaining health.
- Explain various types/classification of food.
- Explain the various functions of food.
- Enumerate the physiology of nutrition.
- Describe nutritional problems in India.
- Discuss national nutrition policies in India.
- Explain the factors affecting food and nutrition.
- Describe the role of medicinal values of food.
- Explain micro and macronutrients.
- Define basal metabolic rate, explain factors affecting BMR.
- Describe the role of nurse in nutrition.
- Nutrition and disease
- Nutritional values of common foods
- Green leafy vegetables
- Five food group plan
- Mineral elements