try wrestling. you will slim down in no time, and you'll gain a lot of muscle. and you'll have a lot of fun doing it. but be warned, if you have a "heart condition" that "stops you from doing sports" or something along those lines, wrestling is not for you. excuse will only serve to get you kicked off the team. if you are serious about losing weight and improving your physic, try wrestling/football/crew(rowing)/a martial art. if you want to do a sport for the sake of doing a sport, then go play basketball or something.
Football might be one of the best sports for you to try. It is very fun and once you play once you will only improve. Just ask your dad to play catch with you one day and if you like it, you should try it!
You could try football, its fun, and enjoyable.... Hope this helps! HAVE FUN!!
football wrestling weightlifting and maybe baseball