GLP-1 medications, such as Ozempic, have significantly transformed the treatment of patients with type 2 diabetes by helping to lower blood glucose levels and support weight loss. However, the effectiveness of these drugs can vary depending on individual patient characteristics. A recent study conducted in Japan found that eating habits and the reasons for overeating can have a substantial impact on long-term therapy outcomes.

Study Design

The study involved 92 people with type 2 diabetes from Gifu Prefecture, Japan, who had just started therapy with GLP-1 receptor agonists. Participants were monitored over 12 months, with measurements taken for body weight, body composition, eating habits, glucose levels, cholesterol, and other health indicators at the start, after three months, and after one year of treatment. Participants also completed questionnaires about their eating behaviors.

Types of Eating Behavior

The research focused on three types of eating behaviors associated with weight gain:

• Emotional overeating — eating to cope with negative emotions rather than due to physical hunger.
• External overeating — eating triggered by the appealing appearance or smell of food, not by hunger.
• Restrained eating — consciously limiting food intake to lose weight. While moderate restraint can be beneficial, excessive restriction may sometimes lead to unhealthy habits.

Main Findings

Overall, study participants reduced their body weight, body fat percentage, and cholesterol levels, while muscle mass remained stable. Blood sugar levels also improved, although the changes were not statistically significant.

Special attention was given to how different eating patterns influenced therapy results. After three months of treatment, participants reported less emotional and external overeating and more restrained eating. However, by the end of the year, emotional and restrained eating scores had mostly returned to baseline. The reduction in external overeating persisted throughout the year, and those who initially had the highest levels of external overeating achieved the greatest success in weight loss and glucose control.

The Impact of Eating Behavior on Therapy Effectiveness

The results showed that GLP-1 receptor agonists were most effective for people prone to overeating in response to external cues, such as the sight or smell of food. For patients whose overeating was mainly driven by emotions or stress, the therapy was less effective. In such cases, additional behavioral or psychological support may be needed.

Study Limitations and Future Perspectives

The study was observational and partly based on self-reported data, which makes it difficult to draw definitive conclusions about causal relationships between eating behavior and treatment outcomes. Additionally, participants may have been especially motivated to improve their diabetes control, which could have influenced weight loss results.

Despite the observed possible link between external overeating and response to GLP-1 therapy, these findings are preliminary. Larger and randomized studies are needed to confirm these results. If confirmed, simple behavioral assessments could become a valuable tool for optimizing treatment strategies for patients with type 2 diabetes.