Please don't lift empty. If you lift an hour after you get up, have some oatmeal, some eggs, cottage cheese... a mixed meal heavier on carbs and protein and lighter on fat.
If you have less time than this, something as simple as toast and cottage cheese, or a whey shake and oatmeal will work fine. Toss a shaker cup with whey in your bag for post workout, eat a bagel or some rice cakes with it for the carbs - or toss some dextrose into the cup with the whey. Even a chocolate milk postworkout will do the trick in a pinch.