GLP-1 drugs such as Ozempic have transformed treatment for many people with type 2 diabetes by lowering blood sugar levels and supporting weight loss. However, researchers are finding that these drugs do not work equally well for everyone. A new study from Japan suggests that a person’s eating habits and the reasons behind overeating may play a big role in the long-term effects of these drugs.
Scientists followed 92 diabetic patients during the first year of treatment with a GLP-1 receptor agonist. The results showed that people who tended to overeat because the food looked or smelled appealing were more likely to experience long-term effects from the drug. In contrast, people who ate primarily in response to stress or emotion were less likely to react in the same way.
“Pre-treatment assessment of eating behavior patterns may help predict who will benefit most from GLP-1 receptor agonist therapy,” said Professor Daisuke Yabe of Kyoto University, lead author of the paper “Clinical Diabetes and Healthcare Frontiers.” “GLP-1 receptor agonists may be effective in people who experience weight gain or elevated blood sugar levels due to overeating due to external stimuli. However, they are less effective if emotional eating is the primary cause.”
Effects of GLP-1 drugs on appetite and weight
GLP-1 receptor agonists lower blood sugar levels in several ways, including increasing insulin release. It also helps many people lose weight by reducing appetite and changing eating behavior. Still, some patients lose a lot of weight, while others see less benefit.
To better understand why, the researchers investigated how participants related to their diet and whether differences in dietary patterns influenced treatment outcomes.
The study involved 92 type 2 diabetic patients living in Gifu Prefecture who had just started GLP-1 therapy. The researchers observed them for 12 months. At the start of treatment, three months later, and again a year later, the team recorded their weight, body composition, eating habits, blood sugar levels, cholesterol, and other health markers. Participants also completed a questionnaire about their eating behavior.
emotional eating and external eating
The researchers focused on three eating patterns commonly associated with weight gain.
The first is emotional eating, where people eat to cope with negative emotions rather than physical hunger. The second is eating out because the food looks or smells appealing, not because you’re hungry. The third type is a “restriction diet,” where you consciously limit your food intake in order to lose weight. Dietary restrictions can support weight loss if balanced, but extreme restrictions can lead to unhealthy eating behaviors.
Overall, participants experienced significant reductions in body weight, body fat percentage, and cholesterol levels during the study. Muscle mass remained stable. Blood sugar levels also improved, but this change was not considered statistically significant.
Why emotional eaters have fewer benefits
The results became even more interesting when researchers compared different dietary patterns.
After 3 months of treatment, participants reported decreased emotional and external eating behaviors and more restrained eating behaviors. However, by the 12-month mark, emotional eating and suppressed eating were almost back to their original levels.
“One possible explanation is that emotional eating is more strongly influenced by psychological factors that may not be directly addressed by GLP-1 receptor agonist therapy,” said Takehiro Kato, Ph.D., of Gifu University, second author of the paper. “People with pronounced emotional eating tendencies may need additional behavioral or psychological support.”
The researchers found no association between emotional or inhibited eating scores at the beginning of treatment and final treatment outcomes one year later. However, a different pattern was observed when eating out. The reduction in eating out continued throughout the year, and participants with the highest levels of eating out at the start of the study experienced the greatest improvements in both weight loss and blood sugar control.
Researchers say more research is needed
The researchers noted several limitations. Because this study was observational and partially relied on self-reported information, it cannot prove that eating behaviors directly caused different treatment responses. Participants may also have been particularly motivated to improve their diabetes management, which may have influenced the amount of weight they lost.
“Our study suggests a potential link between external feeding behavior and treatment response to GLP-1 receptor agonists, but these findings are still preliminary,” Yabe said. “Further evidence is needed before implementation in clinical practice. If future large-scale controlled trials or randomized controlled trials verify this relationship, incorporating simple behavioral assessments could be a valuable element in optimizing treatment strategies.”
