I think it's more about exercise than diet, I've only dropped a couple of lbs in the last year, but my shape's totally changed.
The inches/weightloss isn't quite right I don't think, because inch loss tends to come from change in muscle tone. Muscle's denser than fat, so you can cram a load more muscle into the space where fat would be. So you could stay the same weight, but lose inches cos you're replacing fat with denser muscle. If that makes sense?!