Why do responses to GLP-1 medicines differ? Eating behaviour is one possibility researchers are studying. A 2025 Japanese observational study by Koide and colleagues examined associations between eating patterns and treatment outcomes in people with type 2 diabetes.

GLP-1 eating behaviour research: three patterns

The year-long study enrolled 92 people starting liraglutide, dulaglutide, oral semaglutide or injectable semaglutide. It assessed clinical measures and eating behaviour at the start, three months and 12 months. It was not an Ozempic-only trial. The questionnaires considered three patterns:

  • Emotional eating: Eating in response to negative emotions rather than hunger.
  • External eating: Overeating triggered by appealing sights or smells of food.
  • Restrained eating: Conscious limitation of food intake, which can sometimes lead to unhealthy behaviours if extreme.

Higher baseline external eating scores were associated with greater weight reduction over 12 months, with a trend towards better glycaemic outcomes. Emotional and restrained eating scores were not significantly associated with those clinical outcomes. That does not mean emotional eaters cannot benefit from treatment.

What changed in external and emotional eating?

The finding suggests a research question: might assessment of food-cue responses help explain differences between patients? It is not a validated rule for selecting a medicine or predicting an individual’s weight loss.

While the study found reductions in emotional and external eating behaviours at three months, emotional eating tendencies tended to return by 12 months, unlike external eating, which showed sustained improvement.

Limits of using eating behaviour to predict weight loss

This observational study relied partly on self-reported data and cannot definitively establish causation between eating behaviour and treatment outcomes. Participants were also highly motivated, which may have influenced results. Further large-scale or randomised controlled trials are needed to confirm these findings and explore integrating behavioural assessments into diabetes treatment planning.

The useful implication is to make room for a person’s experience of food in clinical conversations. Medication response should not become a judgement about willpower or a reason to withhold support for distress around eating.

More science explainers and Svelta Labs information are available at https://sveltalabs.com.

Note: This article is for educational purposes based on current research findings. It does not provide medical advice or treatment recommendations.

Sources

Koide and colleagues: GLP-1 eating-behaviour observational study, 2025: https://www.frontiersin.org/journals/clinical-diabetes-and-healthcare/articles/10.3389/fcdhc.2025.1638681/full.