Predicting Weight Loss After Pharmacological or Surgical Treatment in Patients With Obesity

Research of Predictive Factors of Weight Loss After Pharmacological or Surgical Treatment in Patients Suffering From Obesity

As with other nutritional strategies, the clinical response to bariatric surgery can be highly variable, with weight regain being a frequent occurrence. Recent evidence on anti-obesity medication indicate similar inter-individual variability in clinical response. Among multiples factors, co-occurrence of eating disorders such as binge eating disorder has been implicated in insufficient clinical response. Improving our ability to predict how patients will respond to obesity treatment is necessary in order to tailor the care pathways we offer. The mechanisms involved in disturbances of eating behaviour before and after surgery remain largely unknown. This study aims to identify the predictive factors of weight loss after pharmacological or surgical treatment, as well as the cognitive and biological mechanisms that mediate this effect.

Study Overview

• Status: Recruiting
• Conditions: Obesity & Overweight
• Intervention / Treatment: Procedure: Pharmacological or surgical treament of obesity

• Study Type: Observational
• Enrollment (Estimated): 100

Contacts and Locations

• Study Contact: Name: Pr Amandine Everard, Professor; Phone Number: +32 + 32 (0)2 436 22 10; Email: amandine.everard@uclouvain.be
• Study Contact Backup: Name: Yannick Deswysen, Doctor; Phone Number: +32 + 32 2 764 22 13; Email: yannick.deswysen@saintluc.uclouvain.be

Study Locations

• Belgium
  • Brussels Capital
    • Brussels, Brussels Capital, Belgium, 1200
      • Recruiting
      • Cliniques Universitaires Saint-luc
      • Contact: Dr Yannick Deswysen, Doctor; Phone Number: +32 (0) 2 764 22 13; Email: yannick.deswysen@saintluc.uclouvain.be
      • Principal Investigator: Yannick Deswysen, Doctor
      • Sub-Investigator: Audrey Loumaye, Professor

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

• Sampling Method: Non-Probability Sample

Study Population

Participants initiating an anti-obesity medication or candidates for bariatric surgery once its indication has been validated by a multidisciplinary committee, following medical, nutritional and psychological evaluations.

Description

Inclusion criteria:

• Age between 18 and 65 years
• Obesity, with bariatric surgery indicated after a multidisciplinary evaluation in case of surgical treatment.
• Good physical and mental health, enabling informed consent.
• French speaker

Exclusion criteria:

• Legal protection
• Pregnancy or breastfeeding
• History of bariatric surgery (except gastric banding, provided it was removed more than five years ago).
• Acute or progressive chronic disease
• Alcohol consumption of more than 20 g/day
• Inflammatory bowel disease;
• Digestive autonomic diabetic neuropathy.
• Consumption of dietary supplements (stanols, probiotics, prebiotics or omega-3).
• Following a vegan or gluten-free diet or being lactose intolerant.
• Fibre consumption >30 g/day
• Recent change in antidiabetic medication within the past 3 months.

Study Plan

How is the study designed?

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Correlation between weight loss after treatment and clinical, neuropsychological and biological parameters.	The percentage of excessive weight loss after treatment will be correlated with; Clinical parameters (Binge Eating Scale and modified Yale Food Addiction Scale 2.0); Neuropsychological parameter (Barratt Impulsivness Scale and Trail Making Test); Biological parameters	Throughout the entire study, aproximately during 5 years

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Binge Eating Disorder.	Evaluation of eating disorders using the Binge Eating Scale (BES).	Throughout the entire study, aproximately during 5 years
Food Addiction.	Evaluation of food addiction will be performed using modified Yale Food Addiction Scale 2.0.	Throughout the entire study, aproximately during 5 years
Eating attitudes	Eating patterns and habits will be screened using the Eating Attitude Test 26	Throughout the entire study, aproximately during 5 years
Cognitive flexibility.	Neuropsychological evaluation of cognitive flexibility will be performed with the Trail Making Test	Throughout the entire study, aproximately during 5 years
Impulsivity.	Impulsivity will be assessed using the Barrat Impulsiveness Scale (BIS)	Throughout the entire study, aproximately during 5 years
Self-reported quality of life.	Self-reported quality of life will be assessed using the QOLOD (Quality of Life, Obesity and Dietetics)	Throughout the entire study, aproximately during 5 years
Obesity.	Weight will be measured at each timepoint	Throughout the entire study, aproximately during 5 years
Physical activity.	Weekly physical activity will be reported with the Godin Leisure Time Exercise Questionnaire (GLTEQ)	Throughout the entire study, aproximately during 5 years
Food intake.	Eating habits will be recorded with a Food Frequency Questionnaire (FFQ)	Throughout the entire study, aproximately during 5 years
Blood samples	Blood samples will be collected and processed for metabolomic analyses.	Throughout the entire study, aproximately during 5 years
Fecal sample	Feces samples will be collected and processed to evaluation gut-microbiota composition	Throughout the entire study, aproximately during 5 years

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Sociodemographic data	Number of children and marital status will be recorded	Once at inclusion
Medical history	Information concerning medical comorbidities will be collected from the patient medical record.	Once at inclusion
Childhood Trauma.	Assessment of adverse life events and trauma will used the Childhood Trauma Questionnaire - short form.	Once at inclusion

Collaborators and Investigators

• Sponsor: Université Catholique de Louvain
• Investigators: Study Director: Amandine Everard, Professor, Université Catholique de Louvain

Study record dates

Study Major Dates

• Study Start (Actual): May 5, 2026
• Primary Completion (Estimated): June 1, 2032
• Study Completion (Estimated): January 1, 2036

Study Registration Dates

• First Submitted: January 13, 2026
• First Submitted That Met QC Criteria: February 6, 2026
• First Posted (Actual): February 11, 2026

Study Record Updates

• Last Update Posted (Actual): May 14, 2026
• Last Update Submitted That Met QC Criteria: May 11, 2026
• Last Verified: May 1, 2026

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Nutrition Disorders; Overnutrition; Body Weight; Pathological Conditions, Signs and Symptoms; Nutritional and Metabolic Diseases; Signs and Symptoms; Overweight; Obesity; Therapeutics; Surgical Procedures, Operative; Bariatrics; Obesity Management; Bariatric Surgery
• Other Study ID Numbers: TCAPrediBaria

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No