lol if you want to increase weight just eat eat eat.
eat whatever( meat,cheese,noodles,sweets are the best) and just train everyday.
i looked better than most guys in the fitness center stuffing themselves with protein drinks and steroids.
some people actually asked me if i´m taking roids and i said "no and i just do push-ups and train with 5 kilogramm weights"
( which was true)
so in short words, only take that stuff if you really cant gain naturally by eating MUCH and training.