I asked how far you're going, because I believe that nutrition doesn't matter until you get into longer durations (probably 90 mins to 2 hours or longer). Sometimes new riders who are out of shape or not used to riding think that it's because of not eating enough, when in reality they're just not used to riding.
You don't burn that many calories riding (40 to 50 cal per mile is a good estimate). Don't eat extra before rides or you'll eat more then you're burning riding.