Bariatric surgery is widely touted as a drastic but effective method of weight loss. The surgery, which restructures the stomach to limit the amount of food a person can eat, has been successfully performed on thousands of obese patients in the last few decades. However, there are some side effects that are concerning doctors. One of the more worrying is a number of cases in which bariatric surgery seems to have resulted in bone loss.
Weight-loss surgery was first performed in 1954, and the first gastric bypass, the best-known type of bariatric surgery for weight loss, took place in 1966. Gastric bypass—initially using a technique called vertical banded gastroplasty to create a stomach pouch—was a safer procedure than the intestinal bypass that had been performed in the 1950s, which caused patients to become dangerously dehydrated. The modern procedure, called Roux-en-Y anastomosis, was developed more recently. It is one of the most common types of weight-loss surgery, and probably the one most people think of when they think of surgical weight loss.
In this procedure, the intestine, which is normally the output for the whole stomach, is rerouted in a Y shape around most of the stomach and attached to a small pouch. Other surgeries involve a band, sometimes adjustable, around the stomach to limit its capacity. The adjustable band procedure is done laparoscopically, using miniaturized instruments through a small incision, and is one of the safest forms of bariatric surgery available.
Surgical techniques are usually reserved for significantly obese people—meaning a body mass index above 40—or people with a BMI higher than 35 and an obesity-related condition such as type 2 diabetes. In recent years procedures have started to be performed more often on teenagers as well as adults. Unfortunately, teenagers who have had the procedures, particularly Roux-en-Y, performed have shown reduced bone density. A similar though smaller effect has been seen with patients who had the surgery as adults.