Does Iron Man need fuel?

I really like the Iron Man movie, but after watching it for a bazillion time, I just realized something... Does Iron Man need fuel? The suit is basically a machine and machines need fuel, and after shooting some ammo, how does he reload? Wouldn't it be dangerous if he ran out of ammo in a fight? He doesn't have pockets either. P.S. I haven't watch Iron Man 2 so if the answers in there i don't know