Evaluation of factors that may influence in the insufficient weight loss in patients after two years of Roux-en-Y gastric bypass

Introduction: bariatric surgery is a favorable option for the treatment of obesity, resulting in long-term weight loss. Objectives: to analyze whether feeding behavior, evaluated by caloric intake, dietary preferences and tolerance, can be considered as a determinant factor for weight loss in obese patients submitted to Roux-en-Y gastric bypass (RYGB). Methods: cross-sectional study of 105 patients with at least two years post-RYGB surgery with a preoperative body mass index (BMI) of ≥ 35 kg/m². Caloric intake was evaluated by 24-hour dietary recall and 3-day dietary intake record; dietary habits, by a qualitative dietary frequency questionnaire; and food tolerance, with a validated questionnaire. Multiple logistic regression was used for statistical analysis. Results: the majority of the 105 participants were female (84%). The mean age was 43.3 ± 11.4 years in the success group (n = 64) and 43.4 ± 10.7 years in the failure group (n = 41). Preoperative BMI was not associated with the outcome. Mean caloric intake did not show significant differences between groups: 24 hours recall, p = 0.27; 3-day record, p = 0.95. The frequency of weekly consumption of desserts was twice as high in the success group. Only two patients in the success group presented daily vomiting.  Conclusion: the factors that determine the failure of weight loss have not yet been fully elucidated. Caloric intake was not a determining factor of failure, and insufficient weight loss was more prevalent in patients who ceased to lose weight earlier.