I dont find that I need to eat anything special or anything high caloric/carbs for weekly communting unless I ride longer distances on the weekends. When I do that, I need to usually eat more protein in the begining of the week to recover the legs a bit. I think it depends on your commute and how far you have. I have 22 miles RT with only a few slight hills and a lot of wind.

I do, however, try to stay away from foods that might make my stomach upset.