Ana Belén Crujeiras Martínez

GLP-1 medicines for the treatment of obesity show considerable variability between individuals. Using data from 23andMe, scientists at this genetic testing company conducted genome-wide association studies in nearly 28,000 people treated with these drugs, analysing self-reported weight loss and adverse effects. Their findings, published in Nature, identified variations in two genes involved in gut hormone pathways that regulate appetite and digestion, although the authors caution that the effects of genetics appear to be modest.

A meta-analysis published in the Cochrane Database of Systematic Reviews concludes that intermittent fasting is not particularly effective for weight loss in adults who are obese or overweight, who showed moderate weight loss. This strategy also does not differ significantly from standard dietary advice or improvement in quality of life. The review included 22 studies with nearly 2,000 participants and evaluated various forms of intermittent fasting, including restricting food intake for most of the day and fasting every other day.

Patients who are prescribed weight loss drugs may experience a rebound effect after stopping treatment, according to a meta-analysis published in BMC Medicine. The study, which analyses data from patients who received weight loss drugs in 11 randomised clinical trials, suggests that while the amount of weight regained varies depending on the specific drug, there is a general tendency to regain weight once treatment is stopped.