Tamil Nadu HSE Second Year Nutrition and Dietetics key terms

The science of how the body takes in food, breaks it down, absorbs nutrients and uses them for growth, repair, energy and health. It covers nutrients, their functions, requirements and the effects of too little or too much.

Any chemical substance in food that the body uses for energy, building tissues or regulating body processes. Carbohydrates, proteins, fats, vitamins, minerals and water are the six classes of nutrients.

The applied branch of nutrition concerned with planning and adjusting diets for individuals and groups, including people who are ill. It translates nutrient science into practical food choices and therapeutic diets.

A nutrient needed by the body in large amounts and measured in grams. Carbohydrates, proteins and fats supply energy and building material; water is sometimes also counted because of the large daily volume required.

A nutrient needed only in very small amounts, measured in milligrams or micrograms. Vitamins and minerals belong here; they supply no energy but control metabolism, growth and protection against disease.

A set of foods grouped because they provide similar types and amounts of nutrients. Common groups are cereals and millets, pulses and legumes, milk and meat, vegetables and fruits, and fats and sugars.

The five-group classification used in Indian diet planning: cereals and grains, pulses and legumes, milk and meat products, fruits and vegetables, and fats and sugars. Each group contributes a distinct nutrient pattern to the daily diet.

A visual guide placing foods in layers according to how much of them a healthy person should eat. Cereals form the wide base, vegetables and fruits come next, then milk and protein foods, with fats and sweets at the narrow top.

A diet that supplies all essential nutrients in the correct proportions and adequate amounts for a person's age, sex and activity. It includes energy, protein, vitamins, minerals, fibre and water, with variety across food groups.

An energy-giving nutrient built from sugar units, providing about 4 kcal per gram. It includes simple sugars and complex starches and fibre found mainly in cereals, roots, pulses, fruits and sugars.

The indigestible carbohydrate parts of plant foods, such as cellulose, hemicellulose and pectin. Fibre adds bulk, prevents constipation, helps control blood sugar and cholesterol, and is found in whole grains, pulses, vegetables and fruits.

A ranking of carbohydrate foods by how quickly they raise blood glucose compared with a reference food. Low glycaemic index foods are useful in diabetes and obesity management and in planning satiety-promoting meals.

A nutrient made of amino acids, supplying about 4 kcal per gram and used for growth, tissue repair, enzymes, hormones and transport. Body protein depends on both the quantity and the quality of protein eaten.

An amino acid the body cannot make in sufficient quantity, so it must come from food. Histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan and valine are essential for adults.

A measure of how well a protein supplies essential amino acids and how digestible it is. Animal proteins such as egg and milk are usually of high quality; most single plant proteins are limited in one or more amino acids.

The essential amino acid present in the smallest proportion relative to body needs in a given food protein. It restricts how well that protein can be used; combining complementary foods such as cereal and pulse corrects the deficiency.

A broad class of fat-like substances that are insoluble in water, including triglycerides, phospholipids and sterols. Lipids supply about 9 kcal per gram, carry fat-soluble vitamins and provide essential fatty acids.

A fatty acid the body cannot synthesise and must obtain from food. Linoleic acid (omega-6) and alpha-linolenic acid (omega-3) are essential; deficiency affects growth, skin and cell membranes.

A fat whose fatty acid chains carry no double bonds, making it solid at room temperature. It is found in ghee, butter, coconut oil and animal fat; excess intake raises blood cholesterol and heart disease risk.

An organic compound needed in small amounts for normal metabolism, growth and health, which the body generally cannot make. Vitamins are grouped as fat-soluble (A, D, E, K) and water-soluble (B-complex and C).

An inorganic element needed in small amounts for body structure and regulation, such as calcium, iron, zinc and iodine. Minerals are not destroyed by heat, but they can be lost by leaching into cooking water.

A disorder caused by an inadequate intake, absorption or use of one or more nutrients. Examples include anaemia from iron deficiency, rickets from vitamin D deficiency, and night blindness from vitamin A deficiency.

The capacity to do work, supplied to the body by carbohydrate, protein, fat and alcohol and measured in kilocalories or kilojoules. Energy balance exists when intake equals expenditure, keeping body weight stable.

The energy used by a resting, awake person for breathing, circulation, cell activity and temperature control, measured after an overnight fast and rest. It usually forms the largest part of daily energy expenditure.

The sum of all energy a person uses in a day: basal metabolic rate, energy for physical activity, and the thermic effect of food. It determines the energy intake needed to maintain body weight.

Daily nutrient intake levels set to meet the needs of nearly all healthy people in a defined group. In India they are published by the ICMR-National Institute of Nutrition, with values for age, sex and activity.

The systematic collection and interpretation of data to judge a person's or community's nutritional status. It uses anthropometry, biochemical tests, clinical examination and dietary intake data, often summarised as the ABCD approach.

The measurement of body size and proportions, such as weight, height, mid-upper arm circumference and skinfold thickness. These measurements are compared with reference values to detect undernutrition or obesity.

Weight in kilograms divided by the square of height in metres, used to classify weight status. For Asian Indians, values below 18.5 indicate underweight, 18.5 to 22.9 normal, and 23 or above overweight.

The condition of the body resulting from the balance between nutrient intake and nutrient needs. It ranges from good nutrition to undernutrition or overnutrition and is judged using anthropometric, biochemical, clinical and dietary evidence.

The process of choosing and organising foods into meals that meet nutrient needs, suit the family budget and food habits, and use available foods. It considers age, sex, activity, season, religion and the number of people served.

The planned adjustment of a normal diet in consistency, energy content or nutrient composition to meet a specific need. It may involve adding or restricting foods, changing cooking methods, or altering meal frequency and portion size.

A diet planned to treat or manage a disease while meeting as many normal nutritional needs as possible. Examples include low-sodium diets in hypertension, diabetic diets and low-protein diets in kidney disease.

The addition of inferior, harmful or unnecessary substances to food to increase bulk or profit, or the removal of valuable components. Examples include mixing starch in milk powder and dyes in chilli powder.

Methods used to slow spoilage and keep food safe and nutritious for longer periods. Techniques include drying, refrigeration, freezing, canning, salting, sugaring, pickling and the use of chemical preservatives.

The handling, storage and preparation of food so that it does not cause illness or injury. It covers personal hygiene, safe water, clean utensils, proper cooking temperatures and prevention of cross-contamination.

The study and improvement of the nutritional health of population groups rather than individuals. It uses surveys, education, supplementation and food fortification to address problems such as undernutrition and micronutrient deficiencies.

A systematic study of the food eaten by individuals, households or communities over a defined period. Methods include 24-hour recall, food frequency questionnaires, weighed food records and household consumption surveys.