Sorry to take so long. The more full your liver is with carbs the faster your metabolism will be due to optimized thyroid function. When your body has no easy carbs at hand, it will try to spare carbs by breaking down protien in your muscles. But when you have extra carbs such as those stored in the liver, the body is more incline to use other sources. I like to use fruit to be able to power my workouts while still burning fat. When you eat something like an apple, the insulin spike is minimal, allowing your body to keep utilizing fat as fuel, but when your bloodsugar drops, your body will release glaucogen which stimulates the liver to release stored carbs such as fructose, and at the same time it stimulates fat cells to release fat. I leave the complex carbs for when my muscles needs them, such as after a workout.