I'd have thought that so long as I take 1g-1.5g of Protein per lb of body mass, and I lift weights, then I would increase my muscle mass. But I'm reading that I need to increase my overall calorie consumption so that I consume more than I use. Why is that the case? "it is physiologically impossible to gain muscle without a surplus of calories. "eating clean" and eating high protein isnt' going to actually do anything unless there's a surplus of calories." Thanks for any replies. This has puzzled me for a while.