It's FAR more important to worry about what kind of foods he is eating rather than the quantity at this age, if he's hungry feed him, but just ease back on the things like the snacky stuff, add in fruits, raw vegetables are always great or blanched to make it easier for him to suck lol and then plenty of fluids, but make sure you get him to drink water as well as juice, he'll be fine!! I think others have said, when they are so young they regulate their appetite naturally, and he will get slimmer as he starts to crawl and walk.
Don't worry, you have a really sweet and healthy baby!!

My DS is 100% breastfed and he weighs 15lbs at two months. So I wouldn't be too worried.

my son is 8months old and weighs 21lbs. The doc said that it was normal. I don't think your baby is big, just because he is in bigger clothes doesnt really mean much. My son is already n 12month clothes because he is so tall. his father was 6'8 I wouldn't really worry to much about it, he'll grow out of it.

take care