Nutrition is the sum of the processes by which an organism takes in, metabolizes and utilizes food substance for its various biochemical activities. Nutrients are the organic or inorganic substances which help in survival and in maintaining proper health. A nutrient supplies energy to the body, builds and repairs body tissues and regulates the body metabolism.
On the basis of quantity required by the body, nutrients are classified into two categories:
Macronutrients are nutrients required in a large amount: Carbohydrates, fats, proteins and water
Micronutrients are nutrients required in small amount: Vitamins and minerals