The protein content of milk is not very high, 80% of milk is water, and the protein content of milk is between 2.5% and 4%, but milk is rich in whey protein, which is a protein with high nutritional value. Compared with soybeans, the average protein content of soybeans is about 30%, which means that the protein content of soybeans is about 30 grams per 100 grams. The average protein content of meat is about 20%, while the protein content of eggs is about 12 grams of protein per 100 grams.