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bariatric surgery

March 16, 2022 - In the U.S., about 42% of adults are obese, which translates to around 108 million people. Severe obesity, defined as a BMI ≥ 40, affects 9.2% of adults or almost 24 million people. Given these sobering numbers, it goes without saying that effective weight loss therapies are hard to come by. This has led to a rise in bariatric surgery, an invasive treatment that carries many risks, but for a lot of people, offers the best chance of achieving meaningful weight loss. Bariatric surgery used to be considered an extreme, last-resort option for only the most desperate patients. But improved surgical techniques, increased awareness, broader insurance coverage, and wider availability have made it a common procedure. To put it into perspective, in 2020, around 300,000 bariatric surgeries were performed in the U.S., which was equal to the number of cholecystectomies performed.

The two most common bariatric procedures are gastric sleeve and gastric bypass (also called Roux-en-Y gastric bypass). Gastric bypass used to be the prevailing procedure, but around 2013, gastric sleeve surpassed it. Today, more than 60% of bariatric surgeries are gastric sleeve procedures, while gastric bypass makes up less than 20%. Reasons that gastric sleeve has become preferred include lower surgical complication rates, lower reoperation rates, and fewer chronic nutritional deficiencies.

So how do the two procedures compare as far as weight loss? A 5-year study that randomized 217 patients (average baseline weight 273 lbs) to laparoscopic gastric sleeve or gastric bypass found that the average weight loss was similar between procedures, with sleeve patients losing an average of 25% of their baseline weight (73 lbs) and bypass patients losing 28.6% (81 lbs) (p=0.19). Weight loss nadir occurred between 1 and 2 years in both groups. [PubMed abstract]. Similar studies have found that in general, weight loss is slightly greater with gastric bypass [PMID 29340676, 31678062]

What are the risks? As the volume of procedures has increased, so has surgical experience and training. Compared to the early days of bariatric surgery, both procedures have much-improved safety records with current perioperative mortality rates of ≤ 0.2% and 30-day serious complication rates of less than 6%. Gastric bypass tends to have slightly higher acute and chronic adverse events. In the randomized study discussed above, 5-year reoperation/intervention rates were 15.8% in the sleeve group and 22.1% in the bypass group. Because gastric bypass excludes more of the digestive tract, it also carries a higher risk of vitamin and mineral malabsorption.

As bariatric surgery becomes more commonplace, primary care providers need to be aware of the potential long-term risks these patients face. The Straight Healthcare Weight Loss Procedure page provides information on bariatric procedures, including indications, comparative effectiveness, advantages and disadvantages, and recommended postoperative monitoring. See the links below for more.


Weight loss review

Weight loss medications

Calorie calculator