A meta-analysis of 11 trials involving weight loss drugs has highlighted a broad trend in weight regain after the course of medication finishes.
The US FDA has approved six anti-obesity medications (AOMs) for help with weight loss, which includes orlistat, phentermine-topiramate and semaglutide.
A diabetes medication – Glucagon-like peptide-1 (GLP-1) – is also commonly prescribed to assist with weight loss.
Previous studies have shown that weight regain is common once the course of AOM medication comes to an end, prompting new research by Xiaoling Cai, Linong Ji and colleagues which pulled together the findings from 11 studies conducted around the world.
Their meta-analysis covered data from just over 1,500 people being treated with AOMs and 893 people in control groups. Six studies involved GLP-1 receptor agonists (RAs), one focused on GLP-1 and GLP dual RAs, one on orlistat, two on phentermine-topiramate, and one on naltexone-bupriopion.
After controlling for factors including the presence of diabetes and lifestyle changes like diet or exercise, the research team found the medication was linked to substantial weight loss during treatment, but weight regain began eight weeks after stopping. This weight gain continued for an average period of 20 weeks before stabilising.
The team identified that several factors played a part in weight regain, including the type of medication taken and the consistency of participants’ lifestyle change.
For example, those who were treated with tirzepatide for 36 weeks put on almost half the weight previously lost after moving to a placebo.
The authors added: “Different weight regain was observed in subjects with different characteristics.
“Studies with longer follow-up duration are required to further investigate the potential factors associated with weight change after discontinuation of treatment.”
Read more in BMC Medicine.