Originally Posted by
Berniebikes
Assuming that your commuting is entirely new added exercise you can expect to be burning something around around an additional 400 calories per day (lots of assumptions there, but in the ball park). If you keep your intake to what it was prior to beginning commuting, then you could expect to lose approximately a pound a week.
One thing to add here...this is assuming your caloric intake and output are netting to 0 (or close to it) before you started riding. If you were consuming 800 more calories a day than you were expending and don't change your intake, then you start burning 400 a day by commuting, then you can't expect to loose weight since you'll still have a net surplus of 400 calories a day. You would just gain weight slower.