yeah even 4 lbs a week is a lot. With that amount of weight loss there will also be a lot of muscle burnt away too. And your "breasts" wont lose an extreme amount until around 12%. Oh and amomo, if your metabolic rate is, say like 2500 cals, and you go on a 1300 calorie diet, if your on it for a given amount of time then your resting metabolic rate will decrease dramatically, then when you go back up to 2500 calories youll pack on the pounds very easily, eventually your rate will go back to 2500.