Me too 17, but I'm a girl, so I can't tell you that my breasts are very thin. However, I think a former male classmate of mine used to be like you, and now he has helped me lose a lot of weight. I heard that learning is very important. People who study hard lose weight faster, while other boys do sit-ups to reduce their stomachs and do push-ups to exercise their leg chest muscles. They said there were activities like playing basketball. You'd better exercise more and study more. Go to play basketball half an hour after dinner in the evening, and then eat less. The probability of obesity at night is greater than during the day. I wish you success in losing weight.