Patients begin to regain weight as early as 8 weeks after stopping anti-obesity medications, with weight gain continuing through 1 year, according to a new meta-analysis published in BMC Medicine.

The analysis included 1,573 participants receiving anti-obesity medications (AOMs) and 893 controls. Treatments lasted at least 4 weeks, with follow-ups of at least 4 weeks. Medications studied included GLP-1 receptor agonists, orlistat, naltrexone-bupropion, and phentermine-topiramate.

At 4 weeks after stopping treatment, there was no significant difference in weight between groups. However, by 8 weeks, patients previously treated with AOMs showed significant weight regain, which persisted at later time points through the year.

Weight regain was greater in those who had lost more weight during treatment. Participants with a baseline BMI under 35 kg/m² experienced significant regain, while those with BMI 35 or above did not show significant changes.

Patients with type 2 diabetes regained more weight after discontinuation than those without diabetes. Significant weight regain was also seen in users of GLP-1 receptor agonists, including semaglutide and liraglutide, but not with non–GLP-1 drugs.

Ongoing lifestyle interventions did not prevent weight regain after stopping medication. No significant associations were found between weight regain and age, sex, treatment duration, or length of follow-up.

The findings highlight the importance of extended monitoring and further research on maintaining weight loss after stopping anti-obesity drug therapy.

The authors reported no conflicts of interest.

Source: BMC Medicine