Why does he stay skinny at 36?

He told himself he just wasn't built for it. His brother told him something different. 

He hid under baggy shirts his entire adult life. Not for lack of trying. Over a decade of on-and-off gym, same result every time. He assumed he just wasn't built for it, that some guys grow and some guys don't.

His brother explained what was actually happening. 

4.8 stars · 4,000+ reviews