Questions about my metabolism/weight loss?

I'm extremely athletic but I'm finding it difficult too loose this last bit of body fat... I'm 14% body fat but I'm looking for that last bit of definition. I do intense cardio & weight training everyday, but my coaches think it has something to do with my metabolism. They said take some supplements, I've tried the Atkins Diet, but its not giving me the energy I need to keep up with the workouts, but I get the results... Any help? :) thanks, - Frankie