Disordered Eating and Recurrent Weight Gain After MBS

NCT07434557 | Active Not Recruiting

• 1 other identifier: MUDU-SBE-SS-03
• Study Type: observational
• Target: 49
• Locations: 1 country
• Sites: 1

Brief Summary

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.

Conditions

Obesity & Overweight; Bariatric Surgery; Eating Disorders; Emotional Eating; Weight Regain Post Bariatric Surgery

Keywords

Weight Regain; Bariatric Surgery; Emotional Eating; Eating Disorder; Nutritional Status

Outcome Measures

Primary Outcomes (9)

• Change in body weight

  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.

  Postoperative 5-8 years (60-96 months), single assessment

• Change in body mass index (BMI)

  Change in body mass index calculated from measured body weight and height at each assessment

  Postoperative 5-8 years (60-96 months), single assessment

• Change in body fat percentage

  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.

  Postoperative 5-8 years (60-96 months), single assessment

• Change in waist circumference

  Change in waist circumference measured using standardized anthropometric procedures.

  Postoperative 5-8 years (60-96 months), single assessment

• Outcome: Percent total weight loss at nadir (%TWL nadir)

  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.

  Postoperative 5-8 years (60-96 months), single assessment

• Percent total weight loss at current follow-up (%TWL current)

  Current percent total weight loss was calculated as: %TWL = (preoperative weight - current body weight) / preoperative weight × 100.

  Postoperative 5-8 years (60-96 months), single assessment

• Relative weight regain (%RWG)

  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%).

  Postoperative 5-8 years (60-96 months), single assessment

• Eating disorder symptoms assessed by Eating Disorder Examination Questionnaire (EDE-Q)

  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.

  Postoperative 5-8 years (60-96 months), single assessment

• Emotional eating behavior assessed by Emotional Eater Questionnaire (EEQ)

  Emotional eating behavior was assessed using the Emotional Eater Questionnaire (EEQ), a 10-item self-report instrument developed by Garaulet et al. The validated Turkish version was used. The scale evaluates loss of eating control, food preference tendency, and guilt related to eating. Items are scored on a 0-3 Likert scale, with higher scores indicating greater emotional eating behavior. Permission for scale use was obtained.

  Postoperative 5-8 years (60-96 months), single assessment

Secondary Outcomes (5)

• Dietary intake from 3-day food record

  Postoperative 5-8 years (60-96 months), single assessment

• Glycemic parameters

  Postoperative 5-8 years (60-96 months), single assessment

• Lipid profile

  Postoperative 5-8 years (60-96 months), single assessment

• Hematological and iron status parameters

  Postoperative 5-8 years (60-96 months), single assessment

• Vitamin status parameters

  Postoperative 5-8 years (60-96 months), single assessment

Interventions

Observational assessment OTHER

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.

Eligibility Criteria

• Age: 18 Years - 65 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)
• Sampling Method: Non-Probability Sample

Study Population

Adults aged 18-65 years who had undergone metabolic bariatric surgery at least 5 years previously and demonstrated suboptimal clinical response (SCR) or recurrent weight gain (RWG) were included. Participants were evaluated during a single follow-up visit.

You may qualify if:

• Adults aged 18-65 years
• History of metabolic bariatric surgery
• At least 5 years post-surgery
• Individuals presenting either:
• recurrent weight gain after initial successful weight loss, or insufficient weight loss defined as nadir percent total weight loss (%TWL nadir) \<20%.
• Recurrent weight gain (RWG) was defined according to IFSO consensus recommendations. RWG (%) was calculated as:
• RWG (%) = (weight regained / maximum weight loss) × 100
• Participants were categorized using a cut-off value of 30% (RWG ≥30% vs. \<30%).

You may not qualify if:

• Pregnant or breastfeeding individuals
• Acute illness or active infection
• Medical conditions limiting study safety (e.g., cancer, type 1 diabetes, renal or hepatic failure, recent stroke or myocardial infarction, nephrolithiasis, substance abuse, eating disorders, severe depression or other major psychiatric disorders, inflammatory bowel disease, neoplasia, cardiac arrhythmia, heart failure, respiratory failure, or systemic corticosteroid therapy)
• Professional athletes

Sponsors & Collaborators

• Medipol University: lead
• Mudanya University: collaborator

Study Sites (1)

Mudanya Univesity

Bursa, Bursa, 16160, Turkey (Türkiye)

Location

MeSH Terms

Conditions

Obesity; Overweight; Feeding and Eating Disorders; Emotional Eating

Condition Hierarchy (Ancestors)

Overnutrition; Nutrition Disorders; Nutritional and Metabolic Diseases; Body Weight; Signs and Symptoms; Pathological Conditions, Signs and Symptoms; Signs and Symptoms, Digestive; Mental Disorders; Feeding Behavior; Behavior

Study Design

• Study Type: observational
• Observational Model: CASE ONLY
• Time Perspective: CROSS SECTIONAL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Assistant Professor, Principal Investigator

Study Record Dates

• First Submitted: February 16, 2026
• First Posted: February 25, 2026
• Study Start: January 2, 2025
• Primary Completion: September 10, 2025
• Study Completion: March 5, 2026
• Last Updated: February 25, 2026

Record last verified: 2026-02

Data Sharing

• IPD Sharing: Will not share

Locations

TU (1)