The biggest mistake patients make on a low carb diet, is the insane notion that you can eat as much dead animal and fat as you want, and expect to lose weight. You will be less hungry on a low carb diet. You will have more energy on a low carb diet. You will have fewer cravings on a low carb diet. But you absolutely, positively cannot eat as much protein and fat as you want, and expect to lose weight. If you want to lose weight, you have to limit your calories to 1500 a day. Limitng your calories to 1000 a day is even better. 500 calories a day is almost nothing, and very hard to stay on for more than a day or two.