State of the art weight loss dieting is limiting both calories and carbohydrates. You will lose weight about twice as fast on 1500 calories of protein and fat, compared to 1500 calories of carbohydrate. The bet is you also won’t stay on a weight loss diet long enough and consistently enough to lose weight, if your calories are much over 1500 calories a day – because the speed of your weight loss must reinforce and make worthwhile the deprivation of dieting. Meal replacements (bars and shakes) and structured calorie and carbohydrate controlled meals (Healthy Choice, Lean Cuisine, etc.) help. Freely feeding on protein and fat (Atkins) doesn’t work, because you’ll eat too much to lose weight consistently enough to make the carbohydrate deprivation worthwhile. Structure, structure, structure.