I am a personal trainer who owns my own women's boot camp. As a teen and 20's, I yo-yo dieted frequently, covering a range of about 25 pounds. When I began teaching group exercise through my 30's, I was able to keep my weight in check without much effort. Now that 40 is approaching, things have slowed down. I have put on about 18 pounds that were not coming off. I began Atkins on Sept 29th after reading the book in its entirety. So far so good.