When is the "right" time for weight loss surgery?

Dr. Thomas Tsai had performed weight-loss surgery on the beaming woman in front of him only six months before, but she was already a changed person. Dozens of pounds had melted from her physique, lowering not just the number on the scale but her odds of developing potentially life-threatening health problems. A coveted career promotion capped off her fresh sense of confidence.

"She was the same hardworking person she'd been before surgery, but she didn't face the stigma associated with her weight anymore," says Dr. Tsai, a bariatric surgeon at Harvard-affiliated Brigham and Women's Hospital. "Not only did her health improve, but the surgery may have contributed to social and professional benefits."

Also known as bariatric or metabolic surgery — in reference to its effects on both weight and the body's break-down of food into energy — such procedures were once considered a last resort for people carrying 100 or more extra pounds. But clinicians and patients now view weight-loss surgery as a proactive tool to prevent health dangers linked with extreme obesity — including diabetes, heart disease, and sleep apnea — from developing in the first place.

"I see a range of people who are obese but otherwise healthy, and they want to regain control of their health and life. Others are trying to manage the consequences of obesity on their health," Dr. Tsai says. "A paradigm shift has led us to realize that obesity is a medical disease that should be treated effectively with a range of options."

One tool among many

While more than 70% of Americans struggle with overweight or obesity, according to the National Institutes of Health, bariatric surgery is an option for those who are considered morbidly (or severely) obese. This generally translates to a body mass index (BMI) of 40 or greater, or a BMI of 35 or higher in people who also have weight-related health problems, such as high blood pressure, diabetes, high cholesterol, or sleep apnea.

For these people, bariatric surgery can serve as a tool to take off significant weight when diets, exercise, medications, or other treatments haven't worked. Still, it's not an easy way out—only a leg up, Dr. Tsai says. Surgery won't work if patients don't also change their overall approach to food and fitness.

"Weight-loss surgery doesn't turn a marathon into a 100-meter dash, but it takes an uphill road and makes it downhill, and then flat, by changing the body's metabolism," he says. "It doesn't run the race for you."

Most weight-loss surgeries are performed using minimally invasive techniques, meaning surgeons insert small tools through a few dime-sized cuts in the belly. To varying degrees, the procedures reduce the size of the stomach and alter how nutrients are absorbed. Among the most popular versions are sleeve gastrectomy and gastric bypass, with the latter more extensively modifying internal organs to alter digestion and "hunger hormone" levels, Dr. Tsai says. Some people may be candidates for gastric banding, a procedure to place an inflatable tube around the stomach to limit its capacity.

Heap of health benefits

More than 250,000 Americans — mostly women — undergo weight-loss surgery each year, a number Dr. Tsai notes is steadily increasing. The procedures can lower an obese person's risk of premature death by up to 50%, according to the American Society for Metabolic and Bariatric Surgery. "Very few medications or lifestyle changes have such a durable effect on health," he says.

Myriad recent studies have teased out specific health risks that the surgery can improve. A study published online June 3, 2022, by JAMA suggests that adults with obesity who undergo weight-loss procedures have a 32% lower risk of developing cancer and a 48% lower risk of dying from it compared with similar adults who don't have surgery. Obesity raises the risks of developing 13 different types of cancer that together account for 40% of all cancers diagnosed each year, Dr. Tsai says. Notable among them is endometrial cancer.

"There are very powerful reasons for women, especially, to explore whether metabolic surgery is the right option for them," Dr. Tsai says.

Multiple studies have shown that bariatric surgery also reduces the risk of major cardiovascular events, such as stroke and heart attack, and complications from them, Dr. Tsai adds. "Some patients can stop taking many or all of their medications, and sleep apnea and blood sugar levels are shown to improve as well. And for patients who had back or joint pain, their mobility clearly improves."

What results might you expect? Perhaps a loss of 20% to 30% of your body weight, Dr. Tsai says — most of which occurs in the first year after surgery. "It's not a silver bullet, but it can really magnify a healthy lifestyle," he says.

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