All organisms need adequate food or a proper diet with all nutrients for growth and development and to lead a healthy active life. Plants can manufacture their own food in the presence of sunlight with the help of water, carbon dioxide and chlorophyll: a process called as photo -synthesis. However, animals and humans do not have the ability to make their own food. Hence, they have to either depend on plants or other animals. A human being's ability to meet his nutritional needs through diet depends upon the type and quantity of food stuff available to them that they can include it in their diet.
The nutrients of diet derived from the food supply the energy for activity, the structure material for growth and development and regulatory substance for body processes. Other than these physiological functions, food also has the social and the psychological functions to perform. Most of the diet contains almost all nutrients in various proportion. Nutrients are the chemical substances which obtained from food and these nutrients are vital for the body to keep it healthy and alive. Nutrition has the various definition but the most easily explainable states as " The branch of science that deals with the study of nutrients."
A well-balanced diet has all the nutrients in the adequate amount that is being required by the human body. The diet nutrients are Carbohydrate, Protein, Fat Vitamin, Mineral and Water. Out of these Carbohydrates, Proteins, Fats, and Water are called as Macronutrients (which we need in large amount) and Vitamins and Minerals are called as Micronutrients (which we need in the small amount). Carbohydrates, Protein and fat are also called energy providing nutrients (through which we get energy) and Vitamins, Minerals and Water are called as non-energy providing nutrients (through which we don't get energy but these are the most important substances for our body). These days most of the people are suffering with over nutrition, and this may cause only due to excess intake of one or few nutrients in a day than the actual requirement.