Doctors performed a study comparing two versions of weight loss surgery on people with severe obesity. The surgery, called one-anastomosis gastric bypass, was done with either a shorter or longer connection in the digestive system. Both versions helped patients lose similar amounts of weight and improved their diabetes and high blood pressure equally well. However, the shorter version appeared to cause fewer nutritional problems. This suggests that the shorter surgical approach might be just as effective while being safer for patients’ overall health.

The Quick Take

  • What they studied: Whether using a shorter or longer piece of intestine in weight loss surgery affects how much weight people lose and whether they develop nutritional problems
  • Who participated: People with severe obesity who had weight loss surgery at two hospitals in Iran between 2018 and 2021. The study compared those who received the shorter surgical version to those who received the longer version.
  • Key finding: Both surgical approaches helped patients lose the same amount of weight and improved their health conditions equally well. However, the shorter version appeared to cause fewer nutritional deficiencies, which are common problems after this type of surgery.
  • What it means for you: If you’re considering this weight loss surgery, the shorter surgical approach may offer similar weight loss benefits with potentially fewer nutritional side effects. However, this is one study from specific hospitals, so discuss with your surgeon which approach is best for your individual situation.

The Research Details

Researchers looked back at medical records from patients who had already undergone weight loss surgery at two Iranian hospitals over a three-year period. They divided patients into two groups based on the length of intestine used during surgery: one group had a shorter connection (170-180 centimeters) and another had a longer connection (200-250 centimeters). They then compared how well each group did over the next two years by measuring weight loss, nutritional blood tests, and whether their health problems like diabetes and high blood pressure improved.

This type of study is called a retrospective cohort study, which means researchers examined past medical records rather than following new patients forward in time. This approach is useful for comparing two different surgical techniques that are already being used in practice.

Weight loss surgery is an important treatment for people with severe obesity, but doctors have been concerned that the longer surgical version might cause nutritional problems. This study helps answer whether using a shorter version could reduce these risks while still helping patients lose weight effectively. Understanding which surgical approach works best is important for surgeons choosing how to help their patients.

This study examined real patients treated at actual hospitals, which makes the results practical and relevant. However, because it looked at past medical records rather than following patients prospectively, there may be missing information. The study doesn’t specify exactly how many patients were included, which makes it harder to judge the strength of the findings. Results from two specific hospitals in Iran may not apply equally to all populations worldwide.

What the Results Show

Both groups of patients achieved nearly identical weight loss results. The shorter surgical group reduced their body mass index (BMI) by 28.4 points, while the longer surgical group reduced theirs by 28.3 points—essentially the same outcome. This means that using the shorter surgical approach did not compromise weight loss effectiveness.

Both groups also showed excellent improvement in serious health conditions. Among patients who had high blood pressure, 95.6% experienced complete resolution of their condition after surgery. Among patients with diabetes, 90% achieved complete remission, meaning their blood sugar returned to normal levels without medication. These improvements were comparable between both surgical approaches.

Regarding nutritional health, both groups maintained similar levels of important nutrients in their blood, including albumin (a protein), vitamin D, and vitamin B12. These are key markers that doctors monitor to ensure patients aren’t developing serious nutritional deficiencies.

The study noted that iron storage levels (measured by ferritin) were numerically lower in the longer surgical group, suggesting the shorter approach may better preserve iron levels. While this difference wasn’t statistically significant in this study, it points toward a potential nutritional advantage of the shorter surgical approach. This is important because iron deficiency can cause fatigue and other health problems.

Previous research had raised concerns that the longer surgical approach (200-250 cm) might cause more nutritional problems because it bypasses more of the intestine where nutrients are absorbed. This study supports those concerns by showing that the shorter approach (170-180 cm) appears to maintain better nutritional status while achieving equal weight loss. The findings align with growing interest in optimizing surgical techniques to balance weight loss effectiveness with patient safety.

The study has several important limitations to consider. First, the exact number of patients studied wasn’t clearly reported, making it difficult to assess how reliable the findings are. Second, this was a retrospective study looking at past records, so some patient information may be incomplete or missing. Third, the study was conducted at hospitals in Iran, so the results may not apply equally to patients in other countries with different populations or healthcare systems. Finally, the study only followed patients for two years, so we don’t know if differences between the two approaches might appear over longer time periods.

The Bottom Line

If you’re considering one-anastomosis gastric bypass surgery for severe obesity, discuss with your surgeon whether the shorter biliopancreatic limb approach (170-180 cm) might be appropriate for you. The evidence suggests it provides similar weight loss and health benefits as the longer approach while potentially reducing nutritional risks. This recommendation has moderate confidence based on this single study; more research would strengthen the evidence. Always make decisions in consultation with your medical team who understands your complete health picture.

This research is most relevant for people with severe obesity considering weight loss surgery, their surgeons, and healthcare providers who perform these procedures. It’s less relevant for people with mild or moderate weight concerns, as this surgery is typically reserved for severe obesity cases. People who have already had this surgery may find the information interesting but won’t be able to change their surgical approach.

Weight loss typically begins within weeks of surgery, with most significant weight loss occurring over the first 12-18 months. Health improvements like diabetes remission and blood pressure normalization can begin within weeks to months as weight decreases. Nutritional status stabilizes over several months as the body adjusts to the new digestive system. Full assessment of the surgery’s success usually takes 18-24 months.

Want to Apply This Research?

  • Track weekly weight and monthly measurements of key nutrients through blood work: albumin levels, vitamin D, B12, and iron (ferritin). Record any changes in energy levels, which may indicate nutritional status. Note dates when health conditions like diabetes or high blood pressure improve or resolve.
  • Users who have had or are considering this surgery should use the app to monitor their nutritional supplement intake (vitamins, minerals) as prescribed by their doctor. Set reminders for regular blood work appointments to catch any nutritional deficiencies early. Log dietary intake to ensure adequate protein consumption, which is critical after this surgery.
  • Establish a baseline of current weight and nutritional blood work values before surgery. Set monthly check-ins to review weight trends and nutritional markers. Create alerts for when blood work is due (typically every 3-6 months post-surgery). Track long-term trends over 12-24 months to assess whether the shorter surgical approach is maintaining good nutritional status while achieving weight loss goals.

This research describes a specific surgical procedure for severe obesity and is intended for educational purposes only. Weight loss surgery carries significant risks and is only appropriate for people with severe obesity who have tried other weight loss methods. Do not use this information to make decisions about surgery without consulting with qualified bariatric surgeons and your primary care physician. Individual results vary based on many factors including age, overall health, lifestyle, and surgical technique. This study represents one research center’s experience and may not apply to all patients or surgical settings. Always seek personalized medical advice before considering any surgical intervention.