Researchers studied 44 people who had weight loss surgery to understand how their bodies handle sugar differently after the operation. They used a computer model to track blood sugar and insulin levels after eating. The study found that both types of surgery improved how the body processes food, but they worked in different ways. One surgery caused higher sugar and insulin spikes than the other. These findings could help doctors choose the best surgery for each person based on how their body responds to food.

The Quick Take

  • What they studied: How two different types of weight loss surgery affect blood sugar and insulin levels after eating, and whether one surgery works better than the other for managing blood sugar.
  • Who participated: 44 adults with obesity who had weight loss surgery. Half had one type of surgery (RYGB) and half had another type (OAGB). They were checked 6 months and 12 months after their surgery.
  • Key finding: Both surgeries improved how the body handles sugar, but the RYGB surgery caused bigger spikes in blood sugar and insulin after meals compared to OAGB surgery. This suggests the two surgeries affect the body differently.
  • What it means for you: If you’re considering weight loss surgery, these results suggest that different surgeries may affect your body’s sugar control in different ways. Talk with your doctor about which surgery might be best for your specific health situation. This is early research, so more studies are needed before making treatment decisions.

The Research Details

Researchers followed 44 people who had weight loss surgery and measured their blood sugar and insulin levels at specific times after surgery. They used two different tests to measure how the body responds to food: one test used just sugar water, and another used a regular meal with different types of food. They measured blood samples at 6 months and 12 months after surgery to see how things changed over time.

To understand the data, the researchers used a special computer program that could look at each person’s individual response to food and find patterns across the whole group. This computer model helped them see the detailed changes in blood sugar and insulin that happened after eating, rather than just looking at single measurements.

Understanding how different surgeries affect blood sugar control is important because it helps doctors pick the right surgery for each person. Some people might do better with one type of surgery than another based on how their body responds. The computer model approach allows doctors to see detailed patterns in how each person’s body changes, which could lead to more personalized treatment plans.

This study has some strengths: it followed people over time (6 and 12 months), used two different types of tests to measure responses, and used a sophisticated computer model to analyze the data. However, the study is relatively small with only 44 participants, which means the results may not apply to everyone. The study was published in a peer-reviewed medical journal, which means other experts reviewed the work before publication.

What the Results Show

Both types of weight loss surgery improved how the body handles blood sugar. After surgery, people’s blood sugar levels were lower overall, and their blood sugar peaked earlier after eating—meaning the spike happened faster but didn’t last as long.

When researchers compared the two surgery types, they found important differences. The RYGB surgery (which removes part of the stomach and reroutes the intestines) caused bigger increases in both blood sugar and insulin after meals compared to the OAGB surgery (which creates a smaller pouch but doesn’t reroute as much of the intestines).

Interestingly, when people ate a regular meal (mixed meal test) instead of just drinking sugar water, their blood sugar and insulin levels went up more in both cases. This suggests that the type of food matters for how the body responds.

The study found that the improvements in blood sugar control happened at both the 6-month and 12-month checkpoints, suggesting the benefits were sustained over time. The computer model was able to predict individual responses, which could be useful for doctors to understand how each specific patient’s body is responding to surgery.

Previous research has shown that weight loss surgery improves blood sugar control, but this study provides more detailed information about how different surgeries create different patterns of blood sugar and insulin response. The finding that RYGB causes higher insulin spikes than OAGB adds new information that could help doctors choose between procedures.

The study included only 44 people, which is a relatively small group. Results from small studies may not apply to everyone. The study didn’t follow people for a long time after surgery—only up to 12 months—so we don’t know if these differences continue over years. The study also didn’t look at whether these differences in blood sugar responses actually affect long-term health outcomes or weight loss success.

The Bottom Line

If you’re considering weight loss surgery, discuss with your doctor which type might be best for your situation, especially if you have concerns about blood sugar control. These findings suggest that different surgeries may affect your body differently, so personalized choice matters. This research is promising but still early, so base major decisions on conversations with your healthcare team rather than this single study alone. (Confidence: Moderate—based on small study size)

People with obesity considering weight loss surgery, especially those with diabetes or prediabetes, should be aware of these findings. People who have already had weight loss surgery may find it interesting to understand how their surgery affects their body. Healthcare providers choosing between surgical approaches for patients should consider these differences. People without obesity or those not considering surgery don’t need to apply these findings to their own lives.

Based on this study, improvements in blood sugar control appeared within 6 months of surgery and were still present at 12 months. However, individual results vary, and some people may see changes faster or slower than others.

Want to Apply This Research?

  • If you’ve had weight loss surgery, track your blood sugar levels (if you have a glucose monitor) and meal timing for 2-4 weeks. Note what you eat, when you eat it, and any symptoms like dizziness or energy crashes. This helps you see your personal patterns.
  • Use the app to log meals and any blood sugar-related symptoms (energy levels, hunger, shakiness) at the same times each day. Set reminders to eat at consistent times, as surgery changes how your body processes food. Share this data with your doctor to see if your specific surgery type is working well for you.
  • Check in monthly with your logged data to see if your energy levels, hunger patterns, and any blood sugar symptoms are improving over time. If you notice concerning patterns (like frequent dizziness or extreme hunger), share this with your healthcare provider. Track this for at least 6-12 months to see if improvements continue.

This research is informational and should not replace professional medical advice. Weight loss surgery is a serious medical procedure with risks and benefits that vary by individual. If you’re considering bariatric surgery or have had it, consult with your doctor or surgeon about what these findings mean for your specific situation. Do not make decisions about surgery based solely on this study. Always work with qualified healthcare providers who know your complete medical history.