This is deffinatly NOT a calorie reducing diet. Ive tried eating 600 a day, 800, 1000, 1200 calories a day on low fat, healthy diets. I lost nothing ! I eat anywhere from 1200 - 1500 calories a day and the weight is coming off really fast. I do think that you do need to reduce your calories a little, you cant eat as much low carb food as you want, even dr atkins has said that.