Think low-protein diets are the way to go? They are all the latest rage. Some people claim they can extend your life, heal your skin, and cause weight loss. But a new study, which studied excess eating and body fat increase says something different. Low-protein diets gained less weight than normal or above normal protein intake dieters, but lost lean body mass while putting on fat. This is twice as bad. The loss of muscle mass means a slower metabolism while having more body fat. Remember to keep your protein at 1g/lb of body weight per day to maintain your metabolic rate.