Do thin people eat protein powder or muscle powder for fitness?

Whether it is called muscle-building powder or protein powder, its main component is protein, followed by carbohydrates. Generally speaking, the carbohydrate content of muscle building powder will be higher.

However, other additives depend on the ingredient list, and not every muscle-building powder product is the same. However, these small amounts of added ingredients are well known, because some of them are ingredients that enhance sports performance, or targeted trace elements and vitamins, which belong to things that ordinary people should not consume too much.

If you don't have a feasible exercise plan and a complete nutrition plan, and just say that you want to take protein supplement, then it is definitely better to eat "simple" protein powder in this case.