Protein powder isn't bad. Too much, however, is. Just take it a half hour before a workout and somewhere within two hours after mixed in with water or milk or the like and drink it. It helps muscles recover. Preferably lifting weights as that helps increase muscle mass and not gain weight in areas we don't necessarily want it. I agree with everything that everyone else is saying though. Eat nutrient dense foods and small meals throughout the day to rev up your metabolism and keep you eating regularly as well as staying healthy and (if you are working out) getting fit. Honestly, everyone should work out. It is what keeps our appetites going. And peanut butter is one of the best protein rich foods you could have with lots of fats. You should never have a diet that has zero fats in it because that will ultimately harm you because we need fat in our diet. However, too much fat and sugars and the like are bad. Just limit them, but don't cut fat out completely. I'm actually really into nutrition and health and workout out type of things, so I know a lot about this stuff. Good luck!