Originally Posted by Ambulo

With IF, the quantity of food eaten can go down without the metabolism slowing, because insulin stays low and the body can pull calories from the fat stores. Even better if combined with low carb of course. Contrast this with a low calorie diet, where small snacks and meals are consumed throughout the day. Constant insulin spikes, and when insulin is high, the body cannot access fat stores, so if the dieter white knuckles through the hunger, the metabolism has to be slowed so that the body can manage on what is being eaten.