The human body seven nutrients are: carbohydrates, fat, protein, vitamins, minerals, water, dietary fiber. Seven nutrients in the human body to play the role of energy supply, participate in cellular material composition and physiological regulation. Among them, protein, fat, carbohydrates for energy substances, mainly for human activities to provide energy; protein involved in the components of the cell, and involved in material metabolism and physiological regulation. The other water, vitamins, minerals and dietary fiber are not involved in energy supply, but they are involved in the regulation of the body’s various metabolism, to maintain neuromuscular excitability, to maintain the normal permeability of cell membranes, is to maintain the body’s function is essential to the substance. The seven nutrients are present in a variety of foods, generally balanced diet, food diversity will not be seriously deficient.