Well, the so-called protein powder is generally a powder made of purified soybean protein, casein, whey protein (lacking isoleucine), or a combination of the above protein, and its purpose is to supplement protein for people lacking protein. For healthy people, as long as they adhere to a normal diet, the lack of protein will not happen. Milk, eggs, meat, soybeans, wheat and corn contain all kinds of essential amino acids in sufficient quantities and appropriate proportions. As long as we stick to a variety of foods, we can completely meet the human demand for protein, and there is no need to supplement protein powder. Moreover, the psychological enjoyment and sensory stimulation brought by food can not be replaced by protein powder. Excessive intake of protein is not only a waste, but also harmful to human health.