L.T.
Well, first did you know that ADHD is a symptom of something else? He doesn't know how to make friends socially because the impulsitivity. He needs help learning how to socialize. If the core issue are not addressed he will keeping making the same soical mistakes.ADHD is fixable and often made in to a misdiagnosed lable. For example, it could be anxiety. What socail situations make hime nervous then cause hime to be inmpulsive.
Have you asked him what he enjoys doing? I know it may not sound fun to you or how you prefer he spends his time, but it may interest him. How about some activities where he can socialize and make friends, but I would not suggest setting him up in those situations with including professional help( I understand this). If he is self-medicating with food...then I would reccommend seeing the doctor (I underestand how personal this is but I know this issue all to well).
Drama is a great activity for kids with social-emotional issues. Camp is great too! How about a sport that is less team oriented, like golf or tennis. Hope this is helpful. I would spend some individual time talking about his feelings. He is old enough to get a summer job. How about something part-time that would make him feel successful? He likes camp-is he good with kids? Maybe let him sign-up again as a junior camp counselor.