What the high protein diet does is get around the problem of many diets, that you lose fat, but at the same time you lose muscle - the body's calorie burning engine room.
In a typical diet, much of the weight loss comes from muscle wastage. The problem is that your muscles burn calories - the more muscle you have, the more calories you burn, the less muscle you have, the fewer calories you burn, 24/7.
This is huge. By swapping carbs for protein, you can not only lose more weight, but lose fat, not muscle. In addition, the protein-rich diet seems to be particularly effective for people who have high triglyceride levels and carry weight around the stomach - the so called Syndrome X.
Syndrome X is associated with higher risk of coronary disease, amongst others, so reducing stomach fat can improve your health significantly.
So how does the high protein diet work? Researchers attribute the effectiveness to the increase in Leucine. An amino acid, and a key constituent of protein, Leucine, working together with insulin, helps stimulate protein synthesis in muscle.
The result? The protein reduces muscle loss while the lower carbohydrates reduce your insulin levels, allowing you to burn fat.