and don't believe that cunt that said pushups don't do shit. this guy does only bodyweight excersices.
Right now he probably only does bodyweight exercises to cut and tone. He's shredded, how do you think he got there in the first place? Probably a lot of weights. He's probably just doing bodyweight exercises to maintain this physique.
That being said, everyone is different. Some can gain weight a lot easier than others. YOu just have to find out what works best for you.