When people who are overweight and obese stopped taking their weight-loss medications they regained weight faster than those who stopped a diet or exercise program, a new review has found.
Weight loss medications containing semaglutide, the active ingredient in Ozempic and Wegovy, have taken off in popularity. But about half of people with obesity on this class of medications, called glucagon-like peptide agonists or GLP-1s, stop taking it within a year. Studies suggest that most people discontinue their use due to the high cost and adverse gastrointestinal side-effects.
The authors of a review published in Wednesday’s issue of BMJ say it is important to understand weight regain given the risks of diabetes and heart disease from carrying extra pounds.
To shed light on these questions, Sam West, a postdoctoral researcher at the University of Oxford and his co-authors reviewed randomized trials and observational studies on more than 6,000 adults who were overweight or obese and took GLP-1s or older weight-loss medications compared with 3,000 others in behavioural weight management programs.
Participants treated with weight-loss drugs regained on average 0.4 kg/month after stopping treatment, regaining, on average, 4.8 kilograms or 10 pounds in the first year.
Most weren’t followed after that, but researchers used modelling to estimate that risk markers for diabetes and heart disease, such as high cholesterol and high blood pressure levels, would return to pre-treatment levels in less than two years.
“What we found particularly shocking was just how fast weight was regained after people stopped taking medication,” West said in an interview.
People who went off weight-loss medications regained weight almost four times faster than those who stopped exercising or didn’t stick to their diets. The diet plans ranged from group ones like Weight Watchers to “soups and shakes.” People who stopped the behavioural programs also regained weight.
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What it means for Canadians
The bottom line is that new weight loss medications aren’t a quick fix for people living with obesity, said Dr. Sonja Reichert, an associate professor of family medicine at Western University in London, Ont., who treats and studies obesity and diabetes.
“Many of my patients are surprised when I tell them that these medications are long term and this study just really reinforces that message,” Reichert said.
“It makes sense because obesity is a chronic disease and like most of our other chronic diseases, like high blood pressure, we wouldn’t imagine stopping high blood pressure medications once blood pressure is at target.”
Heather White knows the challenges of excess weight and its medical consequences first hand. The 67-year-old from Toronto also has diabetes and was prescribed Ozempic in 2023 to bring down her weight and improve blood sugar control.
White experienced constant nausea while on the drug. “I can’t say it was all that bad,” she said. But the drug’s weight-loss benefits weren’t enough for her to stick with it, and she stopped taking it after seven months.
Heather White tried and stopped an anti-obesity medication. (Maxime Beauchemin/CBC)
For two years, White focused on her food choices without weight-loss medications.
White said she’s now more conscious of what she eats. She started injecting another weight-loss medication, Mounjaro, which includes a newer GLP-1, about two months ago. “Touch wood, I have had no problems with it.”
Boost coping skills for when hunger returns
Part of the challenge is, GLP-1 medications don’t have lasting effects.
Once people stop taking weight-loss medications, the hunger-curbing effects of the drug are removed but their “food environment,” such as ultra-processed foods, remains, and weight tends to return, said Dana Small, a professor at McGill University who holds a Canada Excellence Research Chair in metabolism and the brain.
“I still think that the GLP-1 drugs, as well as the new drugs in the pipeline are incredibly helpful and should be continued to be prescribed,” Small said. “However, we need to couple this with weight-loss maintenance strategies and concerted efforts to change the food environment.”
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West said one of their key findings from that review is that support during treatment, such as nutritional suggestions from a dietitian, helped people to lose more weight.
It’s not clear why people regain weight faster after stopping weight loss medications because it hasn’t been studied, West said.
“Our best guess is that when people follow a behaviour program, they are often given coping skills to deal with their hunger while they’re losing weight,” he said. But once people stop medications, they also need to learn ways to deal with hunger pangs.
“For individuals who do want to reduce or consider stopping the medication, what does that support look like?” said Reichert, who has consulted for makers of weight loss medications. “We really don’t know those answers.”
But Reichert said she’s excited about where the field seems headed: the possibility of better access to medications, such as a pill, lower prices as well as behavioural programs from insurance companies coupled with efforts to reduce the shame and bias people with bigger bodies face to support healthy lifestyle changes.
