Researchers studied 92 people with type 2 diabetes who started taking GLP-1 medications (drugs that help control blood sugar and weight). They wanted to understand why some people respond better to these medicines than others. They discovered that people who tend to eat when they see food around them—rather than eating because they’re truly hungry—actually lost more weight and had better blood sugar control. This suggests that doctors might be able to predict who will benefit most from these medications by looking at eating habits before starting treatment.

The Quick Take

  • What they studied: Whether a person’s eating habits affect how well GLP-1 diabetes medications work for weight loss and blood sugar control
  • Who participated: 92 adults with type 2 diabetes from four hospitals in Japan who were starting GLP-1 medication for the first time. Researchers tracked them for one year.
  • Key finding: People who eat mainly because food is available around them (called ’external eating’) lost significantly more weight and had better blood sugar improvements when taking GLP-1 drugs. These people lost about 8-10% more body weight than those with other eating patterns.
  • What it means for you: If you tend to eat when you see food rather than when you’re hungry, GLP-1 medications might work especially well for you. However, this is one small study, so talk to your doctor about whether these findings apply to your situation.

The Research Details

This was a prospective observational study, which means researchers followed the same group of people over time and recorded what happened naturally—they didn’t randomly assign people to different treatments. All 92 participants started taking one of four GLP-1 medications (liraglutide, dulaglutide, or semaglutide in different forms). Researchers measured their blood sugar, weight, and body fat at the start, after 3 months, and after 12 months. They also asked detailed questions about eating habits using two validated questionnaires: one about food intake and another specifically designed to measure three types of eating behavior—eating when food is visible, eating when stressed or sad, and eating while trying to restrict food.

Understanding which patients will respond best to GLP-1 medications helps doctors make better treatment decisions. Instead of trying medications randomly, doctors could potentially predict success based on eating behavior patterns. This approach, called ‘personalized medicine,’ can save time and money while improving outcomes.

This study has moderate strength. The positive aspects include: it followed people over a full year, used validated measurement tools, and included multiple hospitals. However, limitations include: the relatively small sample size (92 people), all participants were from Japan so results may not apply everywhere, and it was observational rather than a controlled experiment. The researchers couldn’t prove cause-and-effect, only associations.

What the Results Show

After 12 months, GLP-1 medications worked as expected—blood sugar (HbA1c) improved by about 1.5%, body weight decreased by approximately 5-7%, and body fat percentage dropped significantly. The most interesting finding was about eating behavior: people’s tendency to eat when food is visible around them decreased and stayed lower throughout the year. This suggests the medication may actually help change eating habits, not just suppress appetite. People who had higher ’external eating’ scores at the beginning—meaning they were more likely to eat when they saw food—experienced the greatest weight loss benefits. These individuals lost roughly 2-3 kg more than those with lower external eating scores.

Two other eating behavior patterns were measured: emotional eating (eating when stressed or sad) and restrained eating (trying to limit food intake). These showed temporary changes during the first 3 months but returned to baseline by 12 months, suggesting they weren’t strongly affected by the medication long-term. The study found no meaningful connection between these two eating patterns and how well the medication worked.

Previous research showed that GLP-1 medications work by reducing hunger and appetite. This study adds new information by showing that baseline eating behavior patterns—specifically how much someone eats in response to food cues rather than hunger—can predict treatment success. This is a relatively new finding that hadn’t been clearly demonstrated before in this specific way.

The study was relatively small (92 people), which means results might not apply to larger populations. All participants were from Japan, so findings may differ in other countries with different food cultures. The study couldn’t prove that external eating causes better medication response—only that they’re connected. Some people dropped out during the year, which could affect results. The study didn’t include a control group of people not taking the medication, so we can’t be completely sure the medication caused all the changes observed.

The Bottom Line

If you have type 2 diabetes and your doctor is considering GLP-1 medication, mention if you tend to eat when you see food around you. This information might help your doctor predict how well the medication will work for you. However, this should not be the only factor in deciding whether to take these medications—blood sugar levels, other health conditions, and your doctor’s assessment are all important. Confidence level: Moderate (based on one observational study of 92 people).

This research is most relevant for people with type 2 diabetes considering GLP-1 medications, their doctors, and healthcare providers making treatment decisions. It’s less relevant for people with type 1 diabetes or those already taking these medications for a long time. People with eating disorders should discuss these findings carefully with their healthcare team.

Based on this study, most weight loss and blood sugar improvements appeared within the first 3 months, with continued benefits through 12 months. You shouldn’t expect overnight results—give the medication at least 3 months to show its full effects.

Want to Apply This Research?

  • Track eating triggers daily by noting: (1) times you ate when physically hungry vs. when you saw food, (2) weight weekly, and (3) blood sugar readings as recommended by your doctor. Create a simple log with three columns: ‘Hungry?’, ‘Ate anyway?’, and ‘Why?’
  • Use the app to set reminders to eat only when hungry, not when food is visible. Take a photo before eating and note whether you’re actually hungry on a 1-10 scale. Over time, this awareness can help you understand your eating patterns better and work with your medication more effectively.
  • Monthly, review your eating trigger patterns to see if they’re changing. Compare your weight and blood sugar trends to your eating behavior changes. Share this data with your doctor at regular appointments to assess how well the medication is working for you personally.

This research describes associations between eating behavior and medication response in a specific group of 92 Japanese adults. These findings should not replace professional medical advice. GLP-1 medications carry potential side effects and aren’t appropriate for everyone. Before starting or changing any diabetes medication, consult with your healthcare provider who knows your complete medical history. This study suggests eating behavior may influence medication effectiveness, but individual responses vary greatly. Always work with your doctor to determine the best treatment plan for your specific situation.