A meta-analysis published in the journal eClinical Medicine examined 48 studies (including 6 randomized controlled trials with 3226 participants) to determine how much weight patients might regain if they interrupted their GLP-1 agonist treatment. It is the first study to map the full trajectory of recidivism in the absence of a comprehensive treatment regime. After 1 year of cessation, patients regained 60% of the weight lost during initial treatment. Beyond 52 weeks, modelling extrapolations based on non-linear regression assume a plateau effect, with respondents reaching 75% of their starting weight before the effect gradually ceases.
Dr. Emil Panzaru, research director at the Consumer Choice Center, argues for a careful interpretation of the facts: “News reporting may be tempted to jump on the big rebound numbers as an indication of GLP-1 agonists like semaglutide and tirzepatide being ineffective. But the takeaway is, in fact, optimistic. Crucially, respondents with the worst trajectory still saw a drop of at least 5% from their original weight. As the original study notes, a drop of 5-10% is enough for those with a BMI under 35 kg/m2 to mitigate obesity-related heart disease and metabolic complications. Even in the worst-case scenario of poor adherence, GLP-1 agonists still deliver meaningful health benefits.”
Panzaru added: “Of course, this study has limitations too. The gloomiest predictions are based on just six randomized controlled trials out of the 48 studies. The article concedes that most of the included articles had a moderate risk of bias, indicating that their methodological choices influenced the results to some extent. There is no accounting for body composition, meaning we do not know whether some individuals were gaining muscle while losing fat, despite a similar BMI, and there is no way to account for such lifestyle differences in health outcomes. Furthermore, manufacturers recommend a three-year uninterrupted treatment, whereas clinical data usually focuses on only one or two years of GLP-1 outcomes, further biasing results. All these caveats mean we must be cautious about drawing strong conclusions from one analysis.”
Panzaru concluded: “The single most important thing to remember is common sense. GLP-1 agonists are a treatment, not a cure, and being overweight or obese is a long-term condition. It should not be surprising that relapses happen and that progress may be lost. The real issue is not with GLP-1 agonists, but with uptake. The most startling statistic in the article is one that is likely to be overlooked: half of all patients who initiated treatment never obtained long-term transformations because they discontinued treatment within the first year. Therefore, we must focus efforts on encouraging patients not to quit and giving health providers a stake in their patients’ success via models like bundled payments, in which rewards are issued for the completion of a full treatment cycle.”Frederik Roeder and Emil Panzaru have published academic research on the societal and economic benefits of GLP-1 agonists, available here.
