Best Time of Day to Workout

The most important thing is consistency (vs. time of day), so as far as results go, it's best to choose a time when you will be the most consistent.

That said, you want to make sure that you wait 2-3 hours after you've had a meal to give your stomach time to digest before you exercise.  It's okay to have a light snack just before your workout in case you need a little extra energy or if you're feeling hungry.