The protein content of an egg is 6-7g. Because egg yolk contains high cholesterol and fat, it is generally necessary to eat egg yolk for fitness. The protein content of an egg is only 3-4g except the yolk. However, if you take one gram of protein per kilogram of body weight, you need to train hard if you want to achieve good muscle gain. The intensity is exhaustion, and the pain continues the next day. It is the most economical source of protein, the source of protein with the highest absorption rate and the relatively safe source of protein.