This is what I used to gain muscle mass. First as soon as I woke up I drank 24oz. of water with a splash of Apple Cider Vinegar to clean out my system. Then for breakfast I would make some oatmeal about 2servings and while it was hot I stirred in 1tablespoon of crunchy peanut butter. I would also make me a banana peanut butter shake. I cup of soy milk with a whole banana and a tablespoon of peanut butter. Blend it all together and drink up. For snacks I would boil about 7 eggs and take out the yolk and fill the egg whites with peanut butter. This should help you gain alot of weight really fast especially muscle mass.