Protein powder supplements a part of protein for the body, and the body needs more protein to grow muscles. The human body itself does not store protein, and the protein absorbed that day is either utilized or excreted by metabolism. Normal people don't get enough protein, so it's better to add more.

At present, protein powder is mainly composed of soybean protein and whey protein. The absorption and utilization rate of soybean protein is about 65%, and the proportion of methionine in its amino acid pattern is relatively low. The absorption and utilization rate of whey protein is above 95%, which is a good protein, but it will inevitably contain fat and cholesterol. Because the whey protein content of each brand is different, the absorption and utilization rate can not be the same. The content of whey protein is usually not marked, so the overall absorption and utilization rate is about 75%. Official website, a famous brand in China, claims that it is 85%, and the corrected amino acid score of protein digestibility is also equivalent to 0.85.

Protein powder mainly depends on whether the absorption and utilization rate is complete, and there is a standard called protein digestibility to correct the amino acid score. If the score is 1, it is completely absorbed and utilized. At present, only Nutrilite's is like this.

If it is incomplete, the incomplete part needs liver and kidney for metabolism and excretion (85% can be absorbed and utilized, and 15% needs to be metabolized separately). The process of metabolism and excretion will increase the burden of liver and kidney, and will also consume the nutrients and water stored by the body. This is not very cost-effective. For people with poor liver and kidney function, it may also affect their health, because the liver and kidney can't completely dispose of the unusable protein, so they can only return to the blood and become garbage, thus forming toxins to accumulate in the body.