Are you male or female? If male, at 5'7" and 115, then you are about the same size as the smallest pro rider. Ie, if bike performance is your goal, then even the fittest and most weight-mindful in the world don't want or need to be any smaller than you are. In fact a few lbs more of muscle might really increase you on-bike performance.

Anyway, I find that eating good whole-grain carbs I. The 24 hours before a big hard ride, and some fruit right before the ride, means I feel better, ride better, and don't feel as famished afterwards.