Expert Q&A

Gastric bypass surgery: When should you consider it?

I need to lose a lot of weight.  I’ve tried every diet and nothing works. Should I consider gastric bypass surgery?

-Mark from Michigan

The best way to lose weight is to eat fewer calories than you use every day. This is the basic idea behind any diet. In theory, as long as a person sticks to this rule, they will lose weight. In reality, many people find it very difficult to change a lifetime of eating habits. Plus, over time—due to repetitive dieting and overeating—people who are overweight often become very efficient at storing calories as fat.  For some people, mustering the willpower to stick to a very low calorie is almost impossible. 

Bariatric surgeons treat obesity as their specialty. They have developed several techniques that put a roadblock in the path of overeating through surgical alteration of the stomach and/or intestines. One approach is to make the stomach smaller and the food passage narrower so the person is forced to eat only small amounts or suffer abdominal pain and vomiting. The other is to bypass some of the intestine to avoid absorbing some of the calories while simultaneously making the stomach smaller to force the person to eat smaller amounts. 

Both these methods create an unnatural diversion of the stomach and intestines. They work because they force people to eat less or suffer adverse effects. Because normal absorption of nutrients is affected, nutritional supplements are needed. Gallstones can form from the rapid weight loss that occurs. Complications of surgery, such as infection and blood clots, are a risk particularly because overweight people are more likely to have other medical problems that predispose them. 

If you think about it, surgical weight loss is just forced calorie restriction. Gastric bypass is not a simple or easy way to lose weight. It should be reserved for those people whose degree of obesity is a greater risk than the surgery itself.

John Messmer, MD
Contributing Expert

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