This problem involves efficiency. Only egg white contains protein, while other foods such as 100g beef and protein only contain 20g, so in order to supplement 40g protein, you have to eat 200g beef, and the other 160g is other ingredients, such as fat, water, carbohydrates and so on. Eggs are even lower, only 13 grams, milk is only 3 grams and soybeans are as high as 36 grams. So you just want to add protein's words. You have to eat a lot of other things for no reason, and they may also be converted into extra calories and fat, which is not good for your fitness. Therefore, the most efficient way is to eat protein powder, and the protein content can basically exceed 80%.