Background: Gastroesophageal reflux disease (GERD), often associated with obesity, impairs quality of life and can lead to complications. This study compared Fundoplication and Roux-en-Y Gastric Bypass (RYGB) in patients with WHO (World Health Organization) class I and II obesity and refractory GERD. Material and Methods: A single-center, retrospective study analyzed 93 patients (55 Fundoplication, 38 RYGB) with BMI < 40 kg/m² who underwent surgery between January 2018 and September 2021. Preoperative characteristics, surgical outcomes, and postoperative results after three months and after one year were analyzed. Quality of life was assessed using Bariatric Quality of Life (BQL) and Quality of Life in Reflux and Dispepsia (QOLRAD) questionnaires. Propensity-score matching (PSM) was performed using the parameters age, BMI and gender. Results: Patients who underwent RYGB had higher preoperative BMI (35.9 vs. 27.5 kg/m², p < 0.0001) and more metabolic comorbidities. Patients who underwent Fundoplication experienced longer anesthesia (192.5 vs. 112 min, p < 0.0001), operation times (134 vs. 79 min, p < 0.0001), and hospital stays (4 vs. 3 days, p = 0.0003). Complication rates in general (p = 0.0154, after three months) and dysphagia rates in particular (p = 0.0036, after three months and p = 0.0147, after one year) were higher in the Fundoplication group. Preoperatively, patients undergoing RYGB reported poorer quality of life in BQL questionnaires (p = 0.0008). PSM showed less reflux regression in the Fundoplication group after three months (p = 0.0223). Conclusion: Despite higher preoperative BMI and comorbidities, patients undergoing RYGB had shorter operative times and hospital stays. The results suggest RYGB may be preferable for patients with refractory GERD and class I and II obesity, but further research on long-term outcomes is needed.

Background: Predicting postoperative body mass index (BMI) trajectories and long-term type 2 diabetes (T2D) remission after bariatric surgery remains challenging. Existing models often rely on baseline variables only and fail to incorporate dynamic postoperative changes. This study aimed to develop and validate a multicentre machine-learning framework that predicts individualized BMI trajectories and T2D remission using routinely available preoperative data and time-dependent weight evolution. Methods: This multicentre retrospective cohort study included adult patients who underwent Roux-en-Y gastric bypass or sleeve gastrectomy across 11 European centres (2012–2023). Variables with > 30% missing data were excluded; remaining missing values were imputed iteratively. A two-stage approach was used: a regression model predicting postoperative BMI at 3–60 months using an autoregressive design; and a classification model predicting T2D remission using baseline features and predicted BMI trajectories. Internal performance was evaluated with ten-fold and leave-one-clinic-out cross-validation; external validation used an independent cohort from Linköping, Sweden. Results: Of the 11 457 patients initially identified, 9652 patients with complete baseline and follow-up information were used for the analysis. The best BMI model (HistGradientBoosting) achieved a root mean square error (RMSE) of 1.11 kg/m2 (95% confidence interval 1.07 to 1.14) and a mean absolute error (MAE) of 0.62 kg/m2 across clinics; external testing showed an RMSE of 1.12 kg/m2 (95% confidence interval 1.11 to 1.12) and an MAE of 0.63 kg/m2. The T2D remission classifier (XGBoost) obtained a Macro F1 score of 0.88 (precision 0.87, recall 0.88), with an external F1 score of 0.89. Incorporating predicted BMI trajectories improved discrimination compared with baseline-only models (C-index 0.95 versus 0.93). Conclusion: A two-stage machine-learning framework has high predictive performance for postoperative BMI and T2D remission up to 5 years after bariatric surgery. Dynamic incorporation of predicted weight trajectories enhances metabolic risk prediction and supports individualized counselling and postoperative management.

Background: Bariatric surgeries, specifically laparoscopic sleeve gastrectomy (SG) and Roux-en-Y gastric bypass (RYGB), are a common intervention for morbid obesity, significantly affecting food tolerance and quality of eating. Understanding these changes is crucial for improving postoperative care and long-term success. Methods: This observational study at University Hospital Mannheim involved 91 patients, aged between 18 and 65 year, who underwent SG or RYGB between 2009 and 2019. Food tolerance was assessed between 25 days and 117 months after surgery using the validated score by Suter et al. (Food Tolerance Score, FTS) and an additional score evaluating tolerance to specific food groups and quality of life. Data on body composition were collected through Bioelectrical Impedance Analysis (BIA) at follow-up visits. Statistical analyses included linear mixed models to analyze the association of food tolerance with body composition changes. Results: The FTS indicated moderate or poor food tolerance in 62.6% of patients, with no significant differences between SG and RYGB. Considering the results of the additional score, food groups such as red meat, wheat products, raw vegetables, carbon dioxide, fatty foods, convenience food, and sweets were the most poorly tolerated food groups. A total of 57 of the participants had a baseline and follow-up BIA measurement. Postoperatively, a significant reduction in body weight and BMI as well as in BIA parameters (fat mass, lean mass, body cell mass, and phase angle) was found. Quality of life improved after bariatric surgery and 76.9% rated their nutritional status as good or excellent, despite possible food intolerances. Conclusions: Bariatric surgery significantly reduces weight and alters food tolerance. Despite moderate or poor food tolerance, patients reported high satisfaction with their nutritional status and quality of life. Detailed food tolerance assessments and personalized dietary follow-ups are essential for the early detection and management of postoperative malnutrition, ensuring sustained weight loss and improved health outcomes.

Patients with initial body mass index > 50 kg/m² are vastly under-represented in randomized clinical trials demonstrating similar weight loss and diabetes remission rates after sleeve gastrectomy and Roux-en-Y gastric bypass. Propensity score matching 1 : 1 was used to compare outcomes regarding weight loss and diabetes control after sleeve gastrectomy and Roux-en-Y gastric bypass in patients with body mass index > 50 kg/m² between 2012 and 2022 in a cohort from 13 centres in six European countries. The primary endpoint was percentage total bodyweight loss; secondary endpoints were diabetes remission rate and rate of persistent body mass index > 40 kg/m². In total, 3976 of 8160 patients were matched and included in the analysis (1988 in each group). Median age at baseline was 40.0 (range 16–76) years in the sleeve gastrectomy group and 39.5 (15–71) years in the Roux-en-Y gastric bypass group. Median body mass index at baseline was 56.2 (range 50.0–100.0) and 54.3 (50.0–83.9) kg/m², respectively (P < 0.001). The follow-up rate was 70.5% at 1 year and 24.4% at 5 years. Percentage total bodyweight loss at 1 and 5 years after sleeve gastrectomy was 30.2 (2.2–63.7) and 25.4 (–4.8 to 56.0)%, respectively, versus 31.2 (7.4–54.5) and 28.2 (−6.6 to 62.9)% in the Roux-en-Y gastric bypass group (P < 0.001 between groups in both time points). The prevalence of persistent body mass index > 40 kg/m² after 1 and 5 years was 42.7 and 57.6%, respectively, after sleeve gastrectomy versus 24.5 and 39.2% after Roux-en-Y gastric bypass (P < 0.001 between groups in both time points). A 5-year follow-up, the prevalence of a pathological haemoglobin A1c level (> 6.5%) was 12.9% after sleeve gastrectomy and 11.6% after Roux-en-Y gastric bypass (P = 0.323). This study suggests that Roux-en-Y gastric bypass results in greater weight loss than sleeve gastrectomy in patients with body mass index > 50 kg/m², whereas improvements in diabetes appear comparable between procedures.