Originally Posted by davester

From my own experience and from reading the research, I think the answer to that question is that it takes a while for your body to adapt to ketosis (fueling your cells primarily from ketones derived from fat reserves) as a replacement for blood sugar (glucose) that's either circulating or stored in the liver. The reason for this is that our modern american diet is extremely heavy on essentially nonstop carbohydrate consumption (which provides glucose) so we lose the ability to easily switch into ketosis. Once adapted to ketosis, you tend not to get hungry any more because you've got plenty of fuel (fat) to access.