It sounds like you are not getting enough calories, 6 pounds is a lot of weight to lose in 1 week. The healthy goal for weight loss is 1-2 pounds per week. I would suggest only replacing one meal per day with a Blast and eating clean for the other two meals. Maybe add in some healthy snacks like we have in the transformation plan. You could keep track of the number of calories you are consuming on www.myfitnesspal.com. This way you know your daily caloric goal for weight loss and how much you are eating.