food is necessary for survival on the earth all living things need food for growth and development it gives us energy to work like machines needs source of energy and living thing's source of energy is food it gives us nutritional support to our body like vitamins , proteins , carbohydrates , etc. food are obtains by the agriculture done by the farming of human activities . food are of different kinds healthy food and junk food . junk food are unhealthy that which causes diseases i.e. not beneficial for our health and healthy food are the beneficial for our heath which have good nutrition .