High protein diet plans have gone in and out of vogue and they do often present health risks in certain people and body types, however, they can be useful if incorporated into a healthy, full diet with all the vitamins and nutrients you need if you are looking to build muscle or add weight. Protein doesn't always need to come from meat. Many effective high protein diets use protein powders, peanut butter and other sources of protein. It's worth experimenting to find a high protein diet that you can be comfortable with for the best results.