**1.2. Essential nutrient requirements**

In human body, essential element is not synthesized in the adequate amount and body cannot synthesize on its own and must be provided by the nutritional diet. The chemical components present in the food are classified into six major groups like protein, fats, carbohydrates, minerals, vitamins and water. Utilization of nutrients as an essential component requires water. In our body, nutrients are required for the various functions like respiration, digestion, growth and development. The amounts of the essential nutrients required differ by age and the state of the body [3].
