4XL Study - Obesity Surgery in Adolescence (4XL)

4XL-Study - Obesity Surgery in Adolescence

The purpose of this study on adolescents between 13 and 18 years of age with morbid obesity is to determine whether surgical treatment gives more health benefits than standard conservative treatment, and if laparoscopic gastric bypass is a method with high safety and a low complication rate.

Study Overview

• Status: Active, not recruiting
• Conditions: Obesity, Morbid
• Intervention / Treatment: Procedure: Laparoscopic gastric bypass; Behavioral: Standard conservative treatment

Detailed Description

The study has two intervention arms:

Experimental: Group A Surgery; laparoscopic gastric bypass

Active comparator: Group B Patients from Child Obesity Registry of Vestfold who get standard conservative treatment in a multidisiplinary team at Morbid Obesity Center.

All patients are referred to Morbid Obesity Center from other hospitals or general practionairs in Norway. The procedure will take place at the Vestfold Hospital Trust The participants are included for 2 years follow-up with visits to a multidisciplinary team every 3rd month at the Morbid Obesity Center. Total follow-up time is ten years.

• Study Type: Interventional
• Enrollment (Estimated): 120
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Norway
  • Tønsberg, Norway, 3103
    • Morbid Obesity Center, The Hospital of Vestfold, South-Eastern Norway Regional Health Authority

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 13 years to 18 years (Child, Adult)
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Between 13 and 18 years of age at inclusion
• Tanner stage 4-5
• BMI > 40 kg/m2 or BMI > 35 with at least one comorbidity (type 2-diabetes, obstructive sleep apnea, serious hypertension or cerebral pseudotumor)
• At least one year multidisciplinary treatment completed

Exclusion Criteria:

• Tanner stage < 4
• Substantial risk for lack of compliance
• Obesity syndrome (e.g., Prader Willi syndrome)
• Obesity related to brain damage
• Serious general disease
• Monogenic obesity

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Non-Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Group A; Laparoscopic Gastric Bypass	Procedure: Laparoscopic gastric bypass; Patients are referred to Morbid Obesity Center from Vestfold Hospital Trust and other hospitals in Norway. The procedure will take place at Morbid Obesity Center, Vestfold Hospital Trust.
Active Comparator: Group B; Standard conservative treatment. Patients from Child Obesity Registry of Vestfold.	Behavioral: Standard conservative treatment; Participants from Child Obesity Registry who undergoes conservative treatment at Morbid Obesity Center, Vestfold Hospital Trust.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
BMI and weight loss	Surgical or standard conservative treatment	Baseline, Year 1, 2, 5, 10

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Quality of Life (KINDL)	Web-based questionnaire baseline and after 1, 2, 5 and 10 years.	10 years
Eating Disorders (Child Eating Behavior Questionnaire)	Web-based questionnaire baseline and after 1, 2, 5 and 10 years.	10 years
Mental Health (Development and Well-Being Assessment, DAWBA)	Web-based questionnaire baseline and after 1, 2, 5 and 10 years.	10 years
Self-Esteem (Rosenberg Self-Esteem scale)	Web-based questionnaire baseline and after 1, 2, 5 and 10 years.	10 years
Surgical and Medical Complications	Web-based questionnaire baseline and after 1, 2, 5 and 10 years.	10 years
Blood sample results	Blood tests are biobanked at baseline and after 1, 2, 5 and 10 years.	10 years

Collaborators and Investigators

• Sponsor: Sykehuset i Vestfold HF
• Collaborators: The Hospital of Vestfold
• Investigators: Principal Investigator: Samira Lekhal, PhD,MD, Vestfold Hospital Trust/The Hospital of Vestfold; Study Chair: Jøran Hjelmesæth, MD, PhD, Vestfold Hospital Trust/The Hospital of Vestfold

Study record dates

Study Major Dates

• Study Start (Actual): June 1, 2009
• Primary Completion (Estimated): August 1, 2033
• Study Completion (Estimated): December 1, 2035

Study Registration Dates

• First Submitted: June 17, 2009
• First Submitted That Met QC Criteria: June 17, 2009
• First Posted (Estimated): June 18, 2009

Study Record Updates

• Last Update Posted (Actual): April 24, 2026
• Last Update Submitted That Met QC Criteria: April 21, 2026
• Last Verified: March 1, 2026

More Information

Terms related to this study

• Keywords: Adolescents; Mental Health; Quality of Life; Lifestyle; Gastric Bypass
• Additional Relevant MeSH Terms: Nutrition Disorders; Overnutrition; Body Weight; Overweight; Obesity; Pathological Conditions, Signs and Symptoms; Behavior; Nutritional and Metabolic Diseases; Signs and Symptoms; Personal Satisfaction; Obesity, Morbid; Psychological Well-Being
• Other Study ID Numbers: 4XL-2009