Exercise first thing in the morning, your body has enough energy for about 30 min then eat. Start eating a fruit first then 20 min later other things. It increases metabolism and your body uses the nutrition better. Plus fiber is good for you. :)
If you exercise after eating, you won't digest the food, so exercise Ay least an hour after eating. If you can't do that, then eat after exercise. It usually just takes getting used to - I used to run 5 miles before breakfast - once I got used to it, it was great!