A bike is extremely effecient - see Ivan Illich about this. However, say I ride 10 miles and at 35 calories a mile it's 350 calories. One nice iced latte will take care of that right? Especially because unless I remember to tell them not to, they always put whipped cream on top, and those jimmies. I swear, chocolate flavored jimmies! Anyway, what I find is that an hour's brisk ride is very good exercise, I feel like I really exercised when I do an hour against the wind, and it's because I did - that's a fair old ride for someone just getting back into it. Well, I find I actually want to eat less. Yep, exercise for a lot of people has a certain appatite-suppressent effect for a lot of people - look up a file on the net called "Adiposity 101" for that. And, since me no se hable "take it easy" when riding, even when done and when sleeping, my leg muscles are busy recovering and rebuilding, and building up, in response to the stimulus. This is why exercise puts you into a fat-burning mode that's higher than for a nonexerciser that's continuous.

So: That hour's ride burns calories, makes me inclined to actually eat a bit less, and raises my resting metabolism.

Now keep in mind, you really don't want to lose more than one lb a week. It's just not healthy to lose weight faster than that, so you need to treat exercise as a lifestyle change not a band-aid. Likewise with diet. I think in terms not of dieting but as changing habits - out went beer, except occasionally, in came sparkling water, which still feels like a treat. A while back, out went chips, since a small 99-cent bag of fritos is 700+ calories, read the label! Ouch! But I like salad and nuts and things, so those are the new munchies. Frankly I love to sit and crunch through a bag of..... salad fixings (lettuce, carrots, etc that comes in bags) from the store. Yum!

All of this takes CONSISTANCY and TIME so it's a good thing biking is fun!