Weight Loss Surgery May Be More Effective Depending on Your BMI

About 36.5 percent of American adults are obese. Weight loss surgery can help many people achieve a healthy weight, but one recent study finds that the best time to have this surgery may be before someone becomes morbidly obese.

In the study, published in the JAMA Surgery, researchers from the bariatric surgery department at the University of Michigan Health Systems collected data on more than 27,000 people who had weight loss surgery between June 2006 and May 2015. They found that when someone had a body mass index, or BMI, under 40 they were more likely to lose a significant amount of weight and eventually achieve a BMI of under 30 compared to those who started with a higher BMI.

BMI & Weight Loss Surgery

BMI is a measure of your weight in relation to your height. A BMI between 18.5 and 24.9 is considered healthy, 25 to 29.9 is overweight, 30 and over is considered obese and a BMI of 40 or higher is morbidly obese.

In the study, 36 percent of patients had a BMI under 30 a year after their procedure, but less than 9 percent of patients who had a BMI over 50 were able to reduce it to under 30 after surgery. Among those who achieved an under-30 BMI within a year of their procedure, 92 percent said they were really satisfied with their decision to undergo surgery. They also were more likely to report that they no longer took medication for high blood pressure, high cholesterol or high sugar, and that they no longer dealt with issues like sleep apnea.

Researchers also discovered the type of weight loss procedure affected outcomes for patients. Patients who had reversible procedures like gastric banding were less likely to achieve a BMI under 30 than those who underwent permanent procedures like gastric bypass or a duodenal switch.

This study indicates that it may be best to have weight loss surgery before someone becomes morbidly obese. Surgery is often riskier when someone is heavier or has multiple chronic conditions like diabetes or high blood pressure, both of which are linked to obesity. Also, starting at a heavier weight may make it more challenging to lose a lot of weight. For patients who undergo weight loss surgery, the procedure is only the first step. They must eat healthy and practice proper nutrition for the rest of their lives to maintain a healthy weight. Sticking to this can be more challenging when you don’t see results as quickly as you’d like. 

Still, even patients who have a BMI of 40 and above can benefit from weight loss surgery, and in some cases it can be lifesaving. However, this study shows that patients may benefit the most from surgery when their BMI is between 30 and 40. This is valuable information for us to explore as doctors because it’ll help us give patients the best advice about when to have surgery and properly set their expectations for weight loss after their procedure. 

Obesity continues to be an ongoing challenge in our country, but weight loss surgery can help many people get to a healthy weight, and nutritional counseling and ongoing support can help them maintain it long term. But, as this study shows, if you’re a likely candidate for weight loss surgery it may be best not to wait.