I prefer to run/workout on an empty stomach, if I have even the smallest meal I have to leave it a good three hours or I will redecorate the floor! I was like this long before I gave up the carbs too....I will generally exercise for an hour or two when I get up, then when work permits more exercise in the evening providing I haven't eaten too recently. I even did Insanity first thing on an empty stomach, I felt great.