Food is any material consumed to provide nutrition to the organisms. Food is generally of animal, plant or fungal source, and is required to survive in a human or animal body. Food may be divided into three categories: eating food to maintain life; feeding the body without eating; eating to nourish the body parts. Eating and nourishing the body are two completely different functions. The former leads to life, the latter feeds the body or maintains the body’s health.

Food helps to maintain a healthy and strong immune system. A healthy immune system helps to ward off diseases and maintain the body’s normal functioning. To feed the body without eating or nourishing it with food can lead to malnutrition; this leads to diseases such as anemia, osteoporosis and cardiovascular diseases.

Eating right and staying healthy requires an understanding of the food pyramid. According to this pyramid, fruits, vegetables and grains are the major source of food, whereas high levels of dietary fiber are found in beans, nuts, legumes and whole grains. High levels of dietary fiber help the body to digest food more easily, absorbing more nutrients. A healthy diet plan is one that contains high levels of dietary fiber, which is necessary for a healthy diet.