Technically speaking, yeah it's false, but there are people with metabolisms that make it near impossible to gain weight -- I have a few friends like that, one of which is a friend I went to High School with. He at ~8000 calories a day, and it wasn't like his diet was full of fiber and protein and ****, and he didn't gain more than five pounds throughout all of high school. I realize he played football five days a week, but I played Soccer five days a week, ate way less and better calories, and still gained weight throughout high school (not all of which was bulking).