Clinical trial
Disordered Eating and Recurrent Weight Gain After MBS
Active, not recruiting · Not applicable · 1 countries · Registry ID NCT07434557
What this study is about
Obesity represents an increasingly serious public health problem worldwide. According to the World Health Organization, one in eight individuals globally is affected by obesity. Bariatric surgery (BS) is recognized as the most effective treatment for severe obesity and has been shown to significantly improve obesity-related comorbidities. However, despite initially successful surgical outcomes, a substantial proportion of patients experience insufficient weight loss (IWL) or weight regain (WR) after surgery. Previous studies have identified multiple factors associated with post-bariatric IWL and WR, including older age, low socioeconomic status, higher baseline body mass index (particularly preoperative BMI \>50 kg/m²), type of surgical procedure, hormonal mechanisms, poor adherence to postoperative dietary recommendations, maladaptive eating behaviors, insufficient physical activity, and the presence of psychiatric comorbidities. Among these, behavioral factors appear to play a particularly critical role. Irregular eating patterns such as loss of control eating, maladaptive behaviors such as grazing, non-adherence to dietary guidelines, and a return to preoperative eating habits are frequently associated with weight regain. Additionally, physiological mechanisms, including increased appetite, food cravings, and altered hormonal regulation of energy intake, may further contribute to this process. Grazing behavior-defined as repetitive consumption of small amounts of food accompanied by a sense of loss of control-has been consistently associated with poorer weight outcomes after bariatric surgery. A large meta-analysis reported grazing prevalence rates between 16.6% and 46.6%, with weight regain observed in nearly half of post-bariatric patients. Moreover, lack of structured nutritional follow-up has been shown to significantly increase the risk of weight regain. Neurobehavioral changes also occur after surgery: while appetite and responsiveness to palatable foods typically decrease during the first postoperative year, these effects often diminish over time, with hunger, cravings, and portion sizes gradually increasing in some individuals. Long-term weight regain has been closely linked to disordered eating behaviors, including emotional eating, binge eating, compulsive eating, food addiction, and loss of control eating. Recent studies have demonstrated significant associations between weight regain and binge eating disorder, eating disinhibition, and impulsivity. Qualitative research further highlights that many patients struggle to manage emotional eating and require ongoing psychological and dietary support following surgery. Despite growing evidence emphasizing the behavioral and psychological components of post-bariatric outcomes, comprehensive studies that simultaneously evaluate nutritional status, eating disorders, and emotional factors in individuals experiencing IWL or WR remain limited. Therefore, the present study aims to assess nutritional status, eating disorder symptoms, and emotional factors in individuals who experience insufficient weight loss or weight regain after bariatric surgery. By integrating anthropometric, nutritional, behavioral, and emotional assessments within the same sample, this study seeks to provide a multidimensional perspective and contribute to the development of more effective multidisciplinary follow-up and psychodietetic interventions.
Basic eligibility
Full registry criteria
Treatments and study arms
Observational assessment
No intervention was applied. This study is a cross-sectional observational assessment including anthropometric, biochemical, and nutritional evaluations, together with the Eating Disorder Examination Questionnaire (EDE-Q) and the Emotional Eater Questionnaire (EEQ), in individuals experiencing insufficient weight loss or weight regain after bariatric surgery.
Primary outcomes
Change in body weight measured using a calibrated, stationary scale with participants in light clothing and no shoes. Measurements were performed according to standard anthropometric practice to ensure accuracy, with participants instructed to remove heavy garments and accessories before weighing.
Change in body mass index calculated from measured body weight and height at each assessment
Body fat percentage was assessed using bioelectrical impedance analysis (BIA) with a Tanita MC-780 MA analyzer (Tanita Corp., Japan) in accordance with European Society for Clinical Nutrition and Metabolism (ESPEN) guidelines. Measurements were performed under standardized conditions with participants wearing light clothing and barefoot.
Change in waist circumference measured using standardized anthropometric procedures.
Percent total weight loss at nadir was calculated as: %TWL = (preoperative weight - postoperative nadir weight) / preoperative weight × 100. Postoperative nadir weight was defined as the lowest body weight achieved after surgery.
Current percent total weight loss was calculated as: %TWL = (preoperative weight - current body weight) / preoperative weight × 100.
Relative weight regain was calculated according to consensus recommendations as: RWG (%) = (weight regained / maximum weight loss) × 100. Participants were categorized based on a cut-off value of 30% (RWG ≥30% vs. \<30%).
Eating disorder symptoms were assessed using the Eating Disorder Examination Questionnaire (EDE-Q), a 28-item self-report instrument developed by Fairburn et al. The validated Turkish version was used. The questionnaire includes subscales assessing restraint, binge eating, shape concern, eating concern, and weight concern. Items (except binge eating frequency items) are rated on a 0-6 Likert scale, with higher scores indicating greater severity of eating disorder psychopathology. Permission for scale use was obtained.
Study locations
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