Useful, but useless. The protein content of pure milk is too little, only about 5g in a bottle. Strength training costs 1.5 to 2g of protein (if you eat less when you get up the next morning), protein can eat evenly in one day. You don't need to drink protein powder Protein powder is also protein, with a spoonful of 30 to 70g, and the protein content varies (written on the bottle). You can eat more eggs. The protein content of eggs is 13 ~ 15g, and it also contains raw materials for synthesizing hormones. Eating more than 6 eggs a day, plus other meat, is almost enough. If it is a staple food, just make sure that you are not hungry every moment of every day (gain muscle), and don't control the intake of fat too much, because the synthesis of androgen and testosterone requires lipids. But this is not for you to eat fat. Fat quality is not good. You can eat nuts or something. This is unnecessary, just like I didn't eat it.