The nutrients needed by human body can be summarized as protein, lipids, carbohydrates, inorganic salts, vitamins, dietary fiber and water. If one or more nutrients are often lacking in daily life, it will affect your health.

The life activities of human body need energy, which is called heat energy. The energy-producing nutrients in food are carbohydrates, fats and protein. If the human body's long-term heat intake is insufficient or excessive, it will bring harm to health. According to the standards recommended by the Nutrition Society of China, the daily supply of adult males is 10000 joules-16750 joules, and that of adult females is 92 10 joules-0/4235 joules.