A five-year study of 35 women found that sleeve gastrectomy with transit bipartition, a specialized weight loss surgery, helped 77% achieve complete diabetes remission without medications while losing an average of 93 pounds. According to Gram Research analysis, blood sugar levels normalized from 9.2% to 5.5%, but 90% of patients developed nutritional deficiencies requiring lifelong supplementation and medical monitoring.
A new study followed 35 women with severe obesity and insulin-dependent diabetes who had a specialized weight loss surgery called sleeve gastrectomy with transit bipartition. After five years, Gram Research analysis found that nearly 77% of women no longer needed diabetes medication, and they lost an average of 36% of their body weight. However, the surgery did cause some nutritional deficiencies that required lifelong monitoring, including low vitamin D and iron levels in many patients. This research shows the surgery can dramatically improve diabetes control, but patients need ongoing medical supervision.
Key Statistics
A five-year cohort study of 35 women published in 2026 found that 77% of patients achieved type 2 diabetes remission without medications after sleeve gastrectomy with transit bipartition, with average weight loss of 93 pounds.
According to research reviewed by Gram, 73% of women developed vitamin D deficiency and 90% had at least one biochemical abnormality five years after sleeve gastrectomy with transit bipartition, despite the surgery preserving normal intestinal anatomy.
A 2026 single-center cohort study showed that HbA1c levels dropped from 9.2% to 5.5% in women with insulin-treated type 2 diabetes after sleeve gastrectomy with transit bipartition, representing a shift from poorly controlled to normal blood sugar.
Five-year follow-up data from 35 women revealed that 30% developed low iron levels and 20% developed low protein levels after sleeve gastrectomy with transit bipartition, highlighting nutritional risks even with intestine-preserving surgery.
The Quick Take
- What they studied: Whether a specialized weight loss surgery that combines stomach reduction with intestinal rerouting could help women with severe obesity and insulin-dependent type 2 diabetes lose weight and improve their blood sugar control over five years.
- Who participated: 35 women with severe obesity (average starting weight 260 pounds) who required insulin injections to manage their type 2 diabetes. All had the surgery between 2016 and 2017 and were followed for five years.
- Key finding: After five years, 77% of women achieved diabetes remission without needing any diabetes medications, and they lost an average of 79 pounds (36% of their starting body weight). Blood sugar control improved dramatically, with HbA1c levels dropping from 9.2% to 5.5%.
- What it means for you: This surgery appears highly effective for people with severe obesity and insulin-dependent diabetes who have not succeeded with diet and exercise alone. However, patients must commit to lifelong vitamin and mineral supplementation and regular medical monitoring, as the surgery can cause nutritional deficiencies.
The Research Details
Researchers followed 35 women who had a specific weight loss surgery called sleeve gastrectomy with transit bipartition (SG + TB) performed between 2016 and 2017. This surgery combines two techniques: first, the surgeon removes about 80% of the stomach to make it smaller, which reduces how much food a person can eat. Second, the surgeon reroutes part of the small intestine so food bypasses some of the digestive tract, reducing calorie and nutrient absorption.
The researchers collected detailed information about each woman’s weight, blood sugar levels, diabetes medications, and blood tests measuring vitamins and minerals at the start of surgery and then again at the five-year mark. They defined diabetes remission as achieving a blood sugar level below 6.5% without taking any diabetes medications for at least three months. The study was prospective, meaning researchers followed patients forward in time rather than looking backward at medical records.
This was a single-center study, meaning all surgeries were performed at one hospital by the same surgical team. This consistency helps ensure the results reflect the actual surgery technique rather than variations between different surgeons.
Following patients for five years is important because weight loss surgery results can change over time. Some people regain weight or their diabetes returns after a few years. By tracking these 35 women for a full five years, researchers could see whether the benefits lasted and what long-term complications developed. This longer-term data is valuable because most weight loss surgery studies only follow patients for one to two years.
This study has both strengths and limitations. The strength is that it followed the same group of patients over five years with detailed measurements of weight, blood sugar, and nutritional markers. However, the sample size is relatively small (35 women), which means results may not apply to all women or to men. Additionally, 5 of the 35 women either had the surgery reversed or didn’t complete the study, which could affect the results. The study was conducted at a single center by experienced surgeons, so results might differ at other hospitals with less experience in this specific surgery.
What the Results Show
Among the 30 women who kept the surgery intact and completed all measurements, the results were striking. Average blood sugar levels (measured as HbA1c) dropped from 9.2% to 5.5%, which is a normal, healthy level. This means their diabetes was essentially controlled without medication. Average body weight decreased from 260 pounds to 167 pounds, representing a loss of 93 pounds or about 36% of their starting weight.
Most importantly, 23 of the 30 women (77%) achieved complete diabetes remission, meaning they stopped taking all diabetes medications and maintained normal blood sugar levels. When researchers included all 35 women who started the study (even those who had complications or revisions), the remission rate was still 66%, which is remarkably high for a diabetes treatment.
The weight loss was sustained throughout the five-year period, indicating this was not temporary weight loss that returned over time. Most women maintained their weight loss and continued to have good blood sugar control years after surgery.
While the weight loss and diabetes improvement were excellent, the study revealed significant nutritional problems. At the five-year mark, 73% of women had vitamin D deficiency, 30% had low iron levels, 20% had low protein levels in their blood, and 13% had vitamin B12 deficiency. These deficiencies occurred despite the fact that the surgery preserves the normal path of food through the intestines more than some other weight loss surgeries. This shows that even this less aggressive surgery can interfere with nutrient absorption.
Regarding surgical complications, two women needed additional invasive procedures related to the surgery, including one woman who needed the surgery revised. Additionally, four women developed gallstones requiring gallbladder removal. These complications were manageable but show that the surgery carries real risks beyond just nutritional deficiencies.
This study adds important long-term data to a relatively new surgical technique. Sleeve gastrectomy with transit bipartition is newer than traditional weight loss surgeries like gastric bypass, so five-year outcome data is limited. The diabetes remission rate of 77% is comparable to or better than rates reported for gastric bypass surgery in similar patients. However, the high rate of nutritional deficiencies (90% of patients had at least one deficiency) is consistent with what researchers see after other weight loss surgeries, suggesting that any surgery that reduces food intake and nutrient absorption carries this risk.
Several important limitations affect how we interpret these results. First, the study included only 35 women, which is a small sample size. Results from small studies can be less reliable than results from larger studies. Second, 5 women dropped out or had complications, so the final analysis included only 30 women with complete data. This means some of the benefits may be overstated because women who had problems were excluded from the main analysis. Third, this was a single-center study performed by experienced surgeons at one hospital, so results might differ at other hospitals or with less experienced surgical teams. Fourth, the study included only women, so we cannot know if results would be the same in men. Finally, the study did not include a comparison group of people who did not have surgery, so we cannot be certain that all the improvements were due to the surgery rather than other lifestyle changes.
The Bottom Line
For women with severe obesity and insulin-dependent type 2 diabetes who have not achieved good results with diet, exercise, and medications, sleeve gastrectomy with transit bipartition appears to be an effective option. The evidence shows strong benefits for weight loss and diabetes control lasting at least five years. However, this recommendation comes with important caveats: patients must be willing to take vitamin and mineral supplements for life, attend regular medical appointments for blood work, and accept the risks of surgery including potential nutritional deficiencies and the need for additional procedures. This surgery should only be considered after consultation with a bariatric surgeon and a multidisciplinary team including nutritionists and diabetes specialists.
This research is most relevant to women with severe obesity (BMI over 35) who also have insulin-dependent type 2 diabetes and have not succeeded with medical management alone. It may also interest their family members, healthcare providers, and people considering weight loss surgery. This research is less relevant to people with mild obesity, people with type 2 diabetes that is controlled with oral medications, or people who have not tried intensive lifestyle changes. Men should be cautious about applying these results directly since the study included only women.
Based on this study, most weight loss occurs in the first one to two years after surgery, with weight stabilizing by year three. Diabetes remission can occur within weeks to months after surgery as weight decreases. However, the full benefits take time to develop, and patients should expect to see major improvements over the first year to 18 months. The nutritional deficiencies can develop gradually over months to years, which is why lifelong monitoring is essential.
Frequently Asked Questions
Does weight loss surgery cure type 2 diabetes permanently?
This study shows 77% of women achieved diabetes remission lasting at least five years without medications after sleeve gastrectomy with transit bipartition. However, remission is not the same as a cure; diabetes can potentially return if people regain significant weight or stop following dietary guidelines.
What nutritional problems happen after weight loss surgery?
This five-year study found 73% of women developed vitamin D deficiency, 30% had low iron, 20% had low protein, and 13% had vitamin B12 deficiency. These deficiencies require lifelong supplementation and regular blood work monitoring to prevent serious health problems.
How much weight do people lose with sleeve gastrectomy and transit bipartition?
In this study, women lost an average of 93 pounds (36% of body weight) over five years. Most weight loss occurred in the first one to two years, with weight stabilizing afterward. Results vary by individual based on starting weight and adherence to dietary guidelines.
Is weight loss surgery safe for women with severe diabetes?
This study shows the surgery is generally safe with substantial benefits, but carries real risks. Two of 35 women needed additional procedures, and four developed gallstones. All patients developed nutritional deficiencies requiring lifelong management, so this surgery requires commitment to medical supervision.
How long do the benefits of weight loss surgery last?
This five-year study shows benefits were sustained throughout the follow-up period, with weight loss and diabetes remission maintained at year five. However, longer-term data beyond five years is limited, so lifelong monitoring remains essential.
Want to Apply This Research?
- Track weekly weight and monthly blood sugar readings (if available through home testing) to monitor progress toward the goal of weight loss and diabetes remission. Set a target of losing 1 to 2 pounds per week in the first year and then maintaining weight loss in subsequent years.
- Users who have had or are considering this surgery should use the app to log daily vitamin and mineral supplement intake, including vitamin D, iron, vitamin B12, and protein. Set daily reminders for supplements and track any symptoms of deficiency like fatigue or weakness.
- Create a long-term tracking system that reminds users to schedule quarterly blood work appointments to check for nutritional deficiencies. Log results of HbA1c tests, vitamin D levels, iron levels, and protein levels. Set alerts if any values fall outside the normal range to prompt discussion with healthcare providers.
This research describes outcomes from a specialized weight loss surgery performed at a single medical center on 35 women. Results may not apply to all patients, men, or other surgical settings. Weight loss surgery carries significant risks including nutritional deficiencies, surgical complications, and the need for lifelong medical monitoring. This information is educational and should not replace consultation with qualified healthcare providers including bariatric surgeons, endocrinologists, and registered dietitian nutritionists. Anyone considering weight loss surgery should discuss potential benefits and risks thoroughly with their medical team. Patients who have had weight loss surgery must commit to lifelong vitamin supplementation, dietary changes, and regular medical follow-up.
This research translation is published by Gram Research, the science division of Gram, an AI-powered nutrition tracking app.