Philosophy Cut carbohydrates—they make you hungrier. Load up on fats and proteins.
How It Works When the body takes in very few carbs, it gets its energy by burning fat instead of carbs. This occurs when the liver turns stored fat into chemicals called ketones, which are used for fuel (and can give you less-than-fresh breath).
Downside Long-term adherance. It's hard to stick to a diet that restricts such a big chunk of the food pyramid.