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Active, Not Recruiting

NCT Number: NCT07434557

Disordered Eating and Recurrent Weight Gain After MBS

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.

Active, Not Recruiting

This study is active but is not currently recruiting participants.

Key information

Conditions

Obesity & Overweight Bariatric Surgery Behavior Body Weight Eating Disorders Emotional Eating Feeding Behavior Feeding and Eating Disorders Mental Disorders Nutrition Disorders Nutritional and Metabolic Diseases Obesity Overnutrition Overweight Pathological Conditions, Signs and Symptoms Signs and Symptoms Signs and Symptoms, Digestive Weight Regain Post Bariatric Surgery

Age range

18 year–65 year

Sex eligibility

All sexes

Study type

Observational

Primary location

Mudanya Univesity

Bursa, 16160, Turkey (Türkiye)

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • 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%).

Exclusion criteria

  • 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

Treatment and study plan

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.

Primary outcomes

  1. Change in body weight

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

    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.

  2. Change in body mass index (BMI)

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

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

  3. Change in body fat percentage

    Time frame: Postoperative 5-8 years (60-96 months), single 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.

  4. Change in waist circumference

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

    Change in waist circumference measured using standardized anthropometric procedures.

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

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

    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.

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

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

    Current percent total weight loss was calculated as:

    %TWL = (preoperative weight - current body weight) / preoperative weight × 100.

  7. Relative weight regain (%RWG)

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

    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%).

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

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

    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.

  9. Emotional eating behavior assessed by Emotional Eater Questionnaire (EEQ)

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

    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.

Secondary outcomes

  1. Dietary intake from 3-day food record

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

    Dietary intake was assessed using a 3-day food record including one weekend day. Portion sizes were estimated using a standardized food photograph catalog, and standard recipes were consulted when needed. Macro- and micronutrient intake was analyzed using Nutrition Information Systems software (BEBIS 9, Version 9.0, Istanbul, Turkey).

  2. Glycemic parameters

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

    Fasting glucose metabolism markers including fasting blood glucose, HbA1c, and HOMA-IR were recorded after a minimum of 8 hours of fasting.

  3. Lipid profile

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

    Serum lipid parameters including HDL cholesterol, LDL cholesterol, total cholesterol, and triglycerides were recorded after a minimum of 8 hours of fasting.

  4. Hematological and iron status parameters

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

    Hemoglobin, hematocrit, ferritin, and serum iron levels were recorded following at least 8 hours of fasting.

  5. Vitamin status parameters

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

    Serum vitamin B12 and folic acid levels were recorded after a minimum of 8 hours of fasting.

Sponsors and collaborators

Lead sponsor

Medipol University

Other

Collaborators

  • Mudanya University

Registry information

Official study title

Disordered Eating, Emotional Eating, and Nutritional Status in Patients With Recurrent Weight Gain After Metabolic and Bariatric Surgery

Important dates

Study start
2025
Primary completion
2025
Study completion
2026
First posted
Feb 25, 2026
Registry last updated
Feb 25, 2026

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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