Well, if I may play the devil's advocate here, low carb diets do work for some people, especially for a few I know trying to get that bf% way down. I can lose fat on lots of different diets, but that stubborn fat comes off easier for me on a CKD, while retaining decent lean muscle. In fact, i'm on day 5 of this cutting cycle doing a CKD and I feel fine, and am eating much healthier than when I'm bulking. And remember: low carb doesn't have to mean high fat! As for metabolism, leptin and muscle glycogen, isn't that what refeeds are for?