The nutrients needed in the human body can be summarized as proteins, lipids, carbohydrates, inorganic salts, vitamins, dietary fiber and water. If the diet in daily life often lacks one or several nutrients, it will affect the health of the body.

The human body needs energy, called heat, for its life activities. The nutrients in food that produce energy are carbohydrates, fats, and proteins. If the body's long-term caloric energy intake is insufficient or excessive intake will bring harm to the body's health. According to the recommended standards of the Chinese Nutrition Society, the daily supply of adult men is 10,000 joules - 16,750 joules, adult women 9210 joules - 14,235 joules.