JOULE - Metabolic Adaptation to Weight Loss in Response to a Behavioural Lifestyle Program With or Without Semaglutide in Adolescents With Obesity (JOULE-MARS)

January 13, 2026 updated by: McMaster University

JOULE - Metabolic Adaptation to Weight Loss in Response to a Behavioural Lifestyle Program With or Without Semaglutide in Adolescents With Obesity - a Randomized Controlled Trial

The Joule MARS study is a single center, randomized, open label clinical trial aiming to explore the metabolic adaptations that occur in response to weight management in adolescents with obesity. Behavioural lifestyle intervention with and without a pharmacological intervention - semaglutide- will be studied. Study participants will be randomized to one of two groups. Group A will follow a behavioral lifestyle program (BLP) alone for 6 months, followed by BLP and treatment with semaglutide for six months. Group B will be enrolled in BLP and semaglutide from baseline to 6 months. The primary research question will assess, in youth aged 12-17 years diagnosed with obesity and enrolled in a weight management program, if the implementation of a BLP together with semaglutide, compared to the implementation of BLP alone for 6 months leads to less adaptive thermogenesis.

Study Overview

Status

Recruiting

Conditions

Intervention / Treatment

Detailed Description

The Joule MARS (Metabolic Adaptation to weight loss in Response to a behavioural lifestyle program with or without Semaglutide in adolescents with obesity) study is a single-center, randomized controlled trial designed to investigate the effects of a behaviour lifestyle program and the medication semaglutide on resting energy expenditure (REE), work efficiency during standard exercise on a cycle ergometer and related metabolic outcomes in adolescents with obesity. The study will involve two intervention groups:

Group A will participate in a behavioral lifestyle program (BLP) alone for 6 months followed by a combination of semaglutide treatment and a BLP for an additional 6 months.

Group B will receive semaglutide and a BLP for the first 6 months and then terminate the study.

The study objectives are to determine if, in youth aged 12-17 years with obesity and enrolled in a weight management program:

  1. the implementation of a BLP and semaglutide, compared to the implementation of a BLP alone leads to less adaptive thermogenesis (AT) at 6 months;

  2. the implementation of a BLP and semaglutide, compared to the implementation of a BLP alone for 6-month, leads to:

    Less increase in energy work efficiency during standardized exercise

    Differences in BAT activity

    Differences in health-related quality of life (HRQoL)

  3. BLP and semaglutide, compared to BLP alone, lead to improvements in metabolic health measures (including lipids, glycemia, liver enzymes, hepatic fat and hepatic stiffness) after 6 months.
  4. A longer time enrolled in BLP prior to addition of 6 months of semaglutide alters health outcome response to semaglutide.

A comprehensive assessment will be conducted throughout the study. Using whole-room indirect calorimetry, REE and muscle work efficiency, evaluated during standardized physical activity on a cycle ergometer, will be measured. Body composition (Dual energy x-ray absorptiometry and bioelectric impedance analysis), anthropometry (height, weight, waist circumference, BMI, BMI z score (WHO)), metabolic health, health related quality of life, hepatic fat and cold induced brown adipose tissue activity (MRI) will be assessed. Randomization will be managed via the REDCap EDC system.

Study Type

Interventional

Enrollment (Estimated)

74

Phase

  • Phase 4

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact Backup

Study Locations

  • Canada
    • Ontario
      • Hamilton, Ontario, Canada, L8S 4L8
        • Recruiting
        • McMaster University
        • Principal Investigator:
          • Katherine M Morrison, MD FRCPC
        • Contact:
        • Contact:

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Child

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • Youth aged 12-17 years
  • Diagnosed with obesity (BMI ≥2 standard deviations above WHO Reference median)
  • Enrolled in Growing Health Weight Management or Next Step pediatric clinics (ie. have at least one year of the program remaining).

Exclusion Criteria:

  • Any contraindications for MRI (i.e. claustrophobia, implanted metal, metallic injuries recent tattoo or weight >300lb. Ineligible for imaging visit only.
  • Use of atypical anti-psychotics.
  • Use of the following medication classes: (i.e. Beta-blocker medications, Steatogenic medications, Anti-hyperglycemic medications, HIV drugs, Antidepressants, anxiolytic drugs, anti-psychotic drugs, Thyroid drugs, Antiemetic or amphetamine, dextromethorphan and metoclopramide.)
  • Elevated alanine aminotransferase (ALT) > 5 x upper range of normal at screening.
  • Use of glucose lowering or any anti-obesity medication in the previous 3 months.
  • Known monogenic, syndromic or hypothalamic causes of obesity.
  • Diagnosis of type 1 or 2 diabetes mellitus.
  • Prior bariatric surgery or liver transplantation.
  • Alcohol intake exceeding 3 drinks per week or reported cannabis use.
  • Recent history of cigarette smoking (previous 3 months) - ineligible for imaging only.
  • History or family history of multiple endocrine neoplasia 2 or medullary thyroid cancer.
  • History of pancreatitis.
  • Presence of untreated endocrine disorder.
  • History of an eating disorder and / or history of suicidal ideation
  • History of a cardiac condition that precludes exercise testing or unable to have exercise testing done in the GHWM pediatric clinic, inability to use a cycle ergometer.

Participant who does not have a peak power value obtained in the GHWM pediatric clinic

Female who is pregnant, breast-feeding or intends to become pregnant.

Female who refuses to use a means of contraception if sexually active.

Participation in any interventional clinical study within 90 days before screening.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

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

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Active Comparator: BLP, then BLP+semaglutide
Group A will engage in a BLP alone for the first six months of the study, then receive BLP and semaglutide (Wegovy®) for the last six months of the study, beginning with 0.25 mg subcutaneously weekly and being titrated every four weeks up to a maximum of 2.4 mg in approved doses 0.25 mg, 0.5 mg, 1 mg, 1.7 mg, 2.4 mg.
Drug: Semaglutide Pen Injector
Semaglutide will be delivered by a subcutaneous injection using an injectable pen once weekly. Semaglutide is formulated with 5 approved doses (0.25 mg, 0.5 mg, 1 mg, 1.7 mg, 2.4 mg). Treatment will commence with the lowest dose and will be increased every 4 weeks to the maximum tolerable dose where they will remain for the remainder of the treatment. Participants who are taking the drug will have monthly visits to assess any adverse events, dose titration and drug adherence.
Other Names:
  • Wegovy®
Behavioral: Behavioural Lifestyle Program (BLP)
The BLP will be delivered by the Growing Healthy Weight Management (GHWM) pediatric program at McMaster Children's Hospital. GHWM is a family-based program addressing health behaviours (nutritional pattern and eating behaviours, physical activity, sedentary time and sleep) and physical and mental health issues. In Year 1, the program typically includes 2 group sessions and monthly individualized sessions with the participant and their family. The interdisciplinary weight management team is comprised of a registered dietician, exercise physiologist, kinesiologist, social worker and/or psychologist, general pediatrician and pediatric endocrinologists.
Experimental: BLP and semaglutide
In addition to BLP, Group B will receive semaglutide (Wegovy®) titrated to maximal dose tolerated, in approved doses of 0.25 mg, 0.5 mg, 1 mg, 1.7 mg, 2.4 mg subcutaneously weekly for 6 months .
Drug: Semaglutide Pen Injector
Semaglutide will be delivered by a subcutaneous injection using an injectable pen once weekly. Semaglutide is formulated with 5 approved doses (0.25 mg, 0.5 mg, 1 mg, 1.7 mg, 2.4 mg). Treatment will commence with the lowest dose and will be increased every 4 weeks to the maximum tolerable dose where they will remain for the remainder of the treatment. Participants who are taking the drug will have monthly visits to assess any adverse events, dose titration and drug adherence.
Other Names:
  • Wegovy®
Behavioral: Behavioural Lifestyle Program (BLP)
The BLP will be delivered by the Growing Healthy Weight Management (GHWM) pediatric program at McMaster Children's Hospital. GHWM is a family-based program addressing health behaviours (nutritional pattern and eating behaviours, physical activity, sedentary time and sleep) and physical and mental health issues. In Year 1, the program typically includes 2 group sessions and monthly individualized sessions with the participant and their family. The interdisciplinary weight management team is comprised of a registered dietician, exercise physiologist, kinesiologist, social worker and/or psychologist, general pediatrician and pediatric endocrinologists.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Measurement of Adaptive thermogenesis
Time Frame: 6, 12 months
Adaptive thermogenesis will be calculated as the difference between measured and predicted REE after the intervention. Measured REE will be assessed with the participant awake, but at rest, in a whole room indirect calorimeter. Predicted REE will be calculated based on an equation derived using baseline data from this study population as is currently recommended. Variables that will be considered in deriving the equation include fat-free mass, fat mass, age and sex. We will compare adaptive thermogenesis (primary outcome) and work efficiency between the two treatments utilizing linear regression analysis. Separate analyses for males and females will ensure relevance of study findings to both sexes.
6, 12 months

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Brown Adipose Tissue (BAT) activity
Time Frame: From enrollment to 6 months and to 12 months
Relative decline in supraclavicular fat proton density fat fraction after cold exposure as previously published (Ahmed et al., 2021)
From enrollment to 6 months and to 12 months
Changes in energy work efficiency from baseline during standardized exercise
Time Frame: Baseline, 6, 12 months
Energy work efficiency will be measured by measuring the physical activity energy expenditure (PAEE) from cycle ergometry using whole room calorimetry. This will be calculated as follows: Net mechanical efficiency (mechanical efficiency above resting): Ratio of power generated (kcal/min) / (PA EE - REE). One kcal/hour = 1.163 W Thus, [Power (W) x 0.01433 (kcal/min) / (PA EE (kcal/min) - resEE (kcal/min))] x100 = Work efficiency (%)
Baseline, 6, 12 months
Health-related quality of life (HRQoL)
Time Frame: Baseline to 6 months and to 12 months

This will be measured using the Impact of Weight on Quality of Life kids (IWQOL-kids) questionnaire. Score ranges from 0 to 100, with 100 representing the best quality of life. In addition to a total score, there are scores on four domains:

Physical Comfort (6 items)

Body Esteem (9 items)

Social life (6 items)

Family Relations (6 items)
Baseline to 6 months and to 12 months
Total body mass, fat mass and lean mass
Time Frame: Baseline, 6, 12 months
Body composition will be preferentially measured using Dual-energy X-ray absorptiometry (DXA) scans (Lunar PRODIGY Advance 8743; GE, Healthcare, Waukesha, WI). If the participant has a weight exceeding the limits for the machine, Bioelectrical Impedance Analysis (BIA) (InBody 570) will be utilized.
Baseline, 6, 12 months
Hepatic fat content
Time Frame: Baseline, 6, 12 months
Hepatic fat content will be measured via MRI conducted by a technician at St. Joseph's hospital at baseline, 6 months and 12 months using standardized techniques for precision, accuracy and determination of proton density fat fraction (PDFF) quantification of the whole liver
Baseline, 6, 12 months
Hepatic stiffness
Time Frame: Baseline, 6 and 12 months
Hepatic stiffness, an indicator of hepatic fibrosis, will be measured via Magnetic resonance elastography (MRE) using standardized techniques for precision and accuracy.
Baseline, 6 and 12 months
Fasting lipid profile
Time Frame: Baseline, 6, 12 months
Differences in fasting lipids will be collected via fasting bloodwork. The types of lipids that will be collected will be triglycerides, cholesterol, High-density lipoprotein (HDL) and Low-density lipoprotein (LDL) (mmol/L).
Baseline, 6, 12 months
Fasting insulin
Time Frame: Baseline, 6, 12 months
Fasting insulin will be measured with bloodwork collected. HOMA-IR will be calculated to determine insulin resistance
Baseline, 6, 12 months
Hemoglobin A1C
Time Frame: Baseline, 6 and 12 months
Hemoglobin A1C to be measured in laboratory at Hamilton Health Sciences
Baseline, 6 and 12 months
Alanine aminotransferase
Time Frame: Baseline, 3, 6, 9 and 12 months
ALT will be measured in the laboratory at Hamilton Health Sciences
Baseline, 3, 6, 9 and 12 months

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

McMaster University

Collaborators

Canadian Institutes of Health Research (CIHR)
Diabetes Canada

Investigators

  • Principal Investigator: Katherine M Morrison, MD FRCPC, McMaster University

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

June 18, 2025

Primary Completion (Estimated)

December 31, 2027

Study Completion (Estimated)

December 31, 2027

Study Registration Dates

First Submitted

January 6, 2025

First Submitted That Met QC Criteria

February 21, 2025

First Posted (Actual)

February 28, 2025

Study Record Updates

Last Update Posted (Estimated)

January 14, 2026

Last Update Submitted That Met QC Criteria

January 13, 2026

Last Verified

January 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • 18026

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

UNDECIDED

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

product manufactured in and exported from the U.S.

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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