PARIS: When people stop taking the new generation of weight-loss drugs, they pile on pounds four times faster than they would after stopping diets and exercise, according to a new study published Thursday.
But that was mainly because they lost a lot of weight, according to British researchers who conducted the largest and most recent study on the subject.
A new generation of injectable appetite suppressant drugs, called GLP-1 agonists, has become extremely popular in recent years, transforming the treatment of obesity and diabetes in many countries.
They have been shown to help people lose between 15 and 20 percent of their body weight.
“This all seems like good news,” said Susan Jebb, a public health nutrition scientist at the University of Oxford and co-author of a new BMJ study.
However, recent data suggests that “about half of people stop taking these medications within a year,” she told a news conference.
This could be due to common side effects such as nausea or the price – these drugs can cost more than $1,000 per month in the United States.
So the researchers looked at 37 studies that looked at stopping different weight-loss medications, and found that participants gained back about 0.4 kilograms per month.
Six of the clinical trials involved semaglutide – the ingredient used in Novo Nordisk’s Ozempic and Wegovy brands – and tirzepatide used for Eli Lilly’s Mounjaro and Zepbound.
By taking these two drugs, trial participants lost an average of nearly 15 pounds.
However, after stopping treatment, they gained 10 pounds back within a year, which is the longest follow-up period available for these relatively new drugs.
The researchers predicted that participants would return to their original weight within 18 months.
Measures of heart health, including blood pressure and cholesterol levels, also returned to their original levels after 1.4 years.
People who instead followed programs that included diet and exercise — but not medications — lost significantly less weight. But it took them on average four years to regain the lost pounds.
This means that people taking these medications regained weight four times faster.
“A starting point, not a cure”
“Greater weight loss tends to lead to faster weight regain,” explained the study’s lead author, Sam West, of the University of Oxford.
But a separate analysis showed that weight gain was “consistently faster after treatment, regardless of how much weight was lost in the first place,” he added.
This could be because people who have learned to eat healthier and exercise more often continue to do so even when they regain weight.
Jebb emphasized that GLP-1 drugs “are a very valuable tool in the treatment of obesity, but obesity is a chronic relapsing disease.”
“One would expect these treatments to be continued for life, similar to blood pressure medications,” Jebb said.
If so, it would impact how national health systems judge whether these drugs are cost-effective, the researchers pointed out.
“This new data clearly shows that it is a starting point, not a cure,” said Garron Dodd, a metabolic neuroscience researcher at the University of Melbourne who was not involved in the study.
“Sustainable treatment will likely require combination approaches, longer-term strategies, and therapies that reshape how the brain interprets energy balance, not just the amount of food people eat,” he said.
