Protein powder is convenient and can provide the body with high quality proteins, which can be used alone or with common foods such as eggs, milk, honey, etc. depending on the purpose. 1. Protein powder is purified soy protein, whey protein, etc. Whey protein, in particular, is a very suitable source of additional protein for the fitness population and the elderly population because of its well-digested properties. 2. For the elderly, pre- and post-operative patients or people with weight loss needs, protein powder can be used alone to supplement the body’s need for protein. 3. For muscle building/weight gainers, protein powder can be used with other foods, eggs, milk, honey, etc., before, during and after exercise to improve taste and to replenish glycogen to the muscles, as well as to reduce muscle breakdown and promote muscle synthesis. Soy, dairy allergy is not recommended to consume protein powder, the main source of nutrition for the average person should be a balanced and reasonable diet, protein powder is only a complementary dietary role.