Aaron Marino of alpha m. addresses a viewer question regarding pre workout meals. Aaron doesn't eat before going to the gym. And if he's eaten, he waits at least 3-hours before working out.
Your body is going to use the most readily available calories. Your body doesn't want to get rid of stored body fat, so your body will burn what you most recently consumed. You want your system as empty as possible so the calories burned are body fat. If you want to eat before working out, consume food that has a slow release hypoglycemic index such as brown rice and sweet potatoes