Carnie Wilson lost 150 pounds from 300 pounds at one point after gastric bypass surgery. (Gastric bypass in no simple surgery, where doctors reduce your stomach to the size of a walnut and reconnect the small intestine to the new stomach.)
She has since regained some of the weight back. A tablespoon of almond butter at night, and tasting everything you cook for family and friends will do that to you.
What must be emphasized is that gastric bypass is not a miracle weight loss procedure as shown by Carnie’s continued weight struggles post surgery. If a person’s eating behaviors do not change, they will eventually gain their weight back as the body adopts to the new stomach and shorter small intestine.
Which is why Carnie had to diet and exercise vigorously to lose the weight she regained.
http://www.thatsfit.com/2009/10/23/carnie-wilson-weight-loss-reality-tv-show/
Again, the proper strategies to losing weight as emphasized is eating properly and remaining active.