A: The biggest feature of sports nutritional supplements is good absorption. It is no problem to drink protein powder on an empty stomach, and it is recommended to drink whey protein powder on an empty stomach. The protein content of protein powder is relatively high (70%), and protein will not be converted into fat, so the probability of high-protein food being converted into fat is very low, so don't worry. Sleep is an important recovery period for muscles, so we must supplement protein. But if you eat something else before going to bed, it is easy to gain weight.