Emotional eating may blunt effectiveness of GLP-1 weight-loss drugs, study finds

A Japanese study suggests that emotional eating may blunt the weight-loss and metabolic benefits of GLP-1 receptor agonists such as Ozempic and Wegovy. The trial followed 92 adults with type 2 diabetes over a year, grouping participants by eating behavior and tracking weight, BMI, waist circumference, glucose, cholesterol and triglycerides at baseline, after three months and at the 12-month mark. All groups lost weight and showed improvements in blood sugar and lipid levels initially, but emotional eaters were less able to sustain progress over time.

Participants had an average age of 58; just over half were men. They had lived with type 2 diabetes for about 12 years and had an average body mass index of 30. About 40 percent were prescribed an oral form of semaglutide (the active ingredient in Ozempic and Wegovy), 32 percent received the injectable form, 12 percent took dulaglutide and 8 percent liraglutide. Researchers classified them into emotional, external and restrained eating groups based on questionnaires about eating habits. Weight, BMI, waist circumference, fasting glucose, total cholesterol and triglycerides, along with markers of body fat, were measured at the three time points.

At the three-month checkpoint, participants reported more restrained eating and fewer behaviors associated with emotional or external eating. By 12 months, those in the emotional and restrained groups tended to revert to baseline levels, while external eating continued to decrease across the year, suggesting the drugs may work best for individuals who respond to external cues rather than internal distress.

Professor Daisuke Yabe, senior study author and professor of medicine at Kyoto University in Japan, said: "Pre-treatment assessment of eating behavior patterns may help predict who will benefit most from GLP-1 receptor agonist therapy. GLP-1 receptor agonists are effective for individuals who experience weight gain or elevated blood glucose levels due to overeating triggered by external stimuli. However, their effectiveness is less expected in cases where emotional eating is the primary cause."

Dr Takehiro Kato, second study author and professor at Gifu University in Japan, added: "One possible explanation is that emotional eating is more strongly influenced by psychological factors which may not be directly addressed by GLP-1 receptor agonist therapy. Individuals with prominent emotional eating tendencies may require additional behavioral or psychological support."

The researchers cautioned that the study has limitations, including a small sample size. They emphasized that the findings show associations between emotional eating and the effectiveness of GLP-1 agonists rather than direct causes. However, the team noted the results could spur future research into psychological barriers that reduce drug effectiveness and whether simple behavioral assessments could help tailor treatment plans.

"While our study suggests a potential association between external eating behavior and treatment response to GLP-1 receptor agonists, these findings remain preliminary. Further evidence is necessary before they can be implemented in clinical practice. Should future large-scale or randomized controlled trials validate this relationship, incorporating simple behavioral assessments could become a valuable component in optimizing treatment strategies," said Yabe.

Context helps frame the study: about one in eight U.S. adults has reported using Ozempic or similar medications for diabetes or weight loss, while previous research suggests roughly one in five Americans report emotionally eating "often or very often" due to stress or other negative emotions. The study was published in Frontiers in Clinical Diabetes and Healthcare on Tuesday.

Experts caution against drawing firm conclusions from a single small study, but say the findings underscore the potential value of integrating behavioral considerations into pharmacologic approaches for obesity and type 2 diabetes. If validated, clinicians may eventually combine GLP-1 therapies with targeted psychological or behavioral support to maximize weight loss and metabolic benefits.