Its been suggested that caffeine in general aids slightly in weight loss. Coffee, a major source of caffeine for American adults, temporarily suppresses appetite and boosts metabolism for some time. In terms of exercise, coffee helps improve mental focus, increases the bodys efficiency at using fat as fuel, and helps release more calcium stored in muscle, thus increasing power.
It is quite possible that sugary sources of caffeine, such as sodas and energy drinks lead to increased appetite and food cravings.
The caveat is that caffeine, including coffee, may not act the same way in all people, and thus, may not aid in every individuals weight loss.