It's good for your friends to lookout for you...but quite another to sabotage you. You have to do what is best for you. Your friends dont live in your body nor do they live your health concerns. Do your research, talk with others who actually have the band, then decide whats best for you. If you do it and lose weight, tossing your cookies once or twice will seem like nothing. And it may not happen. Nervousness and excitement are expected. Everything worth having takes work. There is only one of you for all time-fearlessly be yourself.