Weight gain is a slow an steady process. Healthy muscle gain is what is required at your age A balanced diet will promote muscle  and over all development. In case of non-vegetarians, there are lots of option to select from. For pure vegetarians there are many combinations of foods that promote muscle growth. I do not favour protein supplements unless you are a sports person. Pulses, Soya, cruciferous vegetables, dairy products and whole cereals promote muscle gain. Along side proper exercise and a healthy lifestyle aids in overall developmemt. For tailor made diet plan feel free to contact me or register at http://ghkritediet.zest.md or drop in a mail at ghk.ritediet@gmail