Why can't I gain weight?
I am 16, 5'11" and I weigh #140. i'v been working out weekly for two months and i'v been trying to eat the right foods and I just can't seem to build any mass. I'm 16 and can still see my ribs some. don't get me wrong I look good but I just want to add more mass and I can't. I haven't gained any weight at all. what's wrong and how do I fix it?