I myself was 140 pounds and 5'3. And also very muscular. I also have alot of muscle. Just don't overeat. I have nothing for breakfast, small lunch, and veggies and fruit for dinner. I exercise 2 hours a bay with my friend and boyfriend. You don't have to exersice too much. Just watch what you eat and try to break a sweat at least 4 times a week. I have lost 20 pounds doing that. GOOD LUCK