[r3drock]

You could get hungrier because of the exercise and therefore eat more, which would prevent weight loss.

[LouisSayers]

After a hard workout I've often felt not all that hungry at all.

Being lazy, sitting on the couch etc seems to have the opposite effect... I also wonder about what our brain consumes visually. If you're watching other people eating and drinking, it kinda makes you want to do the same.

[bigDinosaur]

It depends on the kind of exercise IME. Swimming is one I've found that generates an enormous appetite.