Food and Nutrition
Food is anything, which nourishes the body and has a chemical composition which enables it when swallowed to do one or more of the following.
- Food is required for growth, maintenance, repair, reproduction and energy.
- Supply substances to regulate the production of energy for the process of growth, repair and reproduction.
All the food consumed undergoes chemical change after being taken into the body and being utilized. Food substances are either from plant or animal origin. Some kinds of fungi are also consumed. Yeasts and bacteria are used in the fermentation of many kinds of foods.1
Food is classified as:
- Proteins
- Carbohydrates
- Fats
- Minerals
- Water
- Vitamins
Functional foods are those which helps in development of better health by providing nutrients beyond existing levels. Functional foods contain bioactive agents which are required for the betterment of overall health. Plant sterol is one such example which lowers the cholesterol levels and omega-3 fats has hypolipidemic and antidiabetic effects.2
Types of food
Proteins
Proteins are the building blocks of the body. They contain nitrogen, carbon, oxygen, hydrogen and sulphur or phosphorous. Sources of proteins include meat, eggs, grains, legumes and dairy products. Requirements of proteins are as described below:
- Women aged between 19 and 70 years require 46 g
- Men aged between 19 and 70 years require 56 g
Deficiency of proteins causes kwashiorkor and marasmus. It also leads to reduced mental retardation.1
Carbohydrates
Carbohydrates are important compounds, which provide energy to various activities and maintain heat in the body. Sources of carbohydrates include food containing starch and sugar like vegetables, fruits, cereals, sugars and gums. The daily-recommended intake of carbohydrate is 130 g/day. The dietary fiber required by an adult man is 38 g and 25 g for adult woman.
Fats
Fats are important dietary requirement for energy and heat. Fats are broken down to glycerol and free fatty acids. The free fatty acids are good source of energy. The average daily intake of fat should release 20–35% calories of energy. The fats and carbohydrates are stored in the adipose tissues. Sources of fat include oil, milk and milk products, animal sources etc.
Minerals
Minerals are inorganic elements required by the body in small amounts for the following purposes:
- To act as a catalyst for enzyme activity
- To maintain normal osmotic and electrochemical gradients to support neuromuscular activity and cell membrane transport activity.
Minerals are classified as micro- and macrominerals. Microminerals are required in minute quantities and macrominerals are required in large quantities. Essential minerals are those which are required to support the biochemical processes.1
Minerals and their requirements
Water
Water is an important nutritional fact required the body and constitutes two-thirds the weight of the human body. Requirement of water 3.7 L/day. A standard of 1 mL of water should be present in each calorie of food.6 Enough water should be consumed, as the presence of water in animal and vegetable foods is insufficient.
Nutrition
Nutrition is the science that deals with the composition of food and the way it brings about proper nourishment. Nutrition is also described as the essential part of the food, which is required by the body to function properly. The nutritional requirements are measurable quantities of the nutrients and are fixed upon age, sex, height, weight, degree of activity and rate of growth.
Malnutrition is the failure of the body to get the nutrients required by the body. A malnourished person is prone to be affected with disease conditions due to the specific nutrient deficiencies, which can affect all the organs of the body.