Our body needs nutrients such as fats, carbohydrates, minerals, vitamins or proteins. Any substance which provides nutrition to the body is food. Usually we consume rice, wheat and maize. The food we eat must have balanced diet. Malnutrition is a big concern in the modern society. People are taking junk foods which hurt them more.
If you want to maintain your body then you have avoid junk foods, over-eating, fasting too much. You have to eat easily digestible foods which make the mind calm and your body supple and light. Further it gives a great resistance power to overwhelm diseases. You have to take more water between meals. During Yoga practice you have to take plenty of water. For the illness you have to take natural remedies except emergencies.