A systematic review published on 19 October 2026 in Obesity Reviews pooled 25 studies of GLP-1-based medicines in 4,060 adults with overweight or obesity and found that the drugs reduced how much people ate in the short term and modestly increased their sense of appetite suppression. The finding is less tidy than it sounds. The studies disagreed sharply with one another, only four were judged at low risk of bias, and the authors say nausea may have shaped the results.
What the review found
The review, by Clarissa Dakin of the University of Leeds with colleagues at Sheffield Hallam and Leeds Beckett universities, searched four databases on 4 November 2025 for studies of GLP-1-based treatments in adults with a body-mass index of 25 or more and no major comorbidities. Participants were 64% women, with a mean age of 44 and a mean BMI of 36.7. Energy intake and overall appetite suppression were meta-analysed; other outcomes, such as food craving and food reward, were summarised in words because the studies measured them too differently to pool.
For energy intake, the pooled standardised mean difference was −0.775, with a 95% confidence interval of −1.21 to −0.34. A standardised difference expresses an effect in units of the variation between people rather than in calories, so it cannot be converted into a calorie figure from the abstract; by the usual rule of thumb, a value near 0.8 counts as a large effect. The interval excludes zero, but heterogeneity was high (I² of 82.7%), and the prediction interval, the range in which a new study of the same kind would be expected to land, included no effect at all.
Appetite suppression rose by a mean difference of 7.8 (95% CI 3.74 to 11.86). The abstract does not state the scale it was measured on, so the size of that change cannot be judged from the summary alone. The studies summarised qualitatively suggested reductions in food craving and in some measures of food reward.
How this fits what was known
That GLP-1 medicines make people eat less is not new; reduced intake is the main proposed route to their weight loss, alongside slower stomach emptying. What this review adds is a measure of how consistently that shows up when eating is actually quantified, and the answer is: in the same direction, but with very different sizes from one study to the next. That matters for the growing conversation about cravings and “food noise” on these drugs, which has so far been described largely through what patients report.
It also connects to the site’s coverage of gastrointestinal side effects. The authors note that nausea was more frequent on active treatment. A participant who feels sick may eat less for reasons that have little to do with appetite regulation, and side effects can reveal which arm of a trial someone is in, which weakens the blinding that self-reported appetite scores depend on. For background on how these drugs work, see our GLP-1 research hub.
What is not yet known
The pooled effects describe short-term intake and do not show how eating changes over months or years of treatment. Only four of the 25 studies were at low risk of bias, the authors had to impute variance data, and outcome measures varied; they cite all three as reasons the size and consistency of the effect remain uncertain. The search ended in November 2025, so trials published since are not included, and the abstract does not break results down by drug or dose. We read the published abstract; the full paper was not accessible to us, so the list of included studies and drug-by-drug detail are not reported here.
Sources: Dakin C, Beaumont JD, O’Hara B. “Influence of GLP-1-Based Pharmacotherapies on Eating Behavior, Appetite, and Energy Intake in Adults With Overweight or Obesity: A Systematic Review and Meta-Analysis.” Obesity Reviews, published online 19 October 2026; PubMed record 42897694.
