Metabolic Adaptations to Weight Loss With and Without Exercise

NCT ID: NCT05806801

Last Updated: 2025-04-08

Basic Information

• Recruitment Status: RECRUITING
• Clinical Phase: NA
• Total Enrollment: 68 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2023-07-19
• Study Completion Date: 2028-05-31

Brief Summary

Study Purpose:

The combination of caloric restriction and exercise is the most common first-line treatment for obesity-related disorders, yet we know very little about how these two very different treatments work together. A deeper understanding about mechanisms underlying the health benefits of adding exercise to a weight loss program will not only aid efforts to optimize more effective lifestyle interventions, but it can also uncover novel targets for the treatment/prevention of obesity-related diseases.

Although a reduction in body fat is the fundamental adaptation to weight loss, we know almost nothing about the effects that adding exercise has on structural and functional changes within fat tissue that may further enhance metabolic health. This is very important because many obesity-related metabolic health complications are tightly linked with abnormalities in abdominal fat tissue. We argue exercise-induced modifications in abdominal fat tissue will reveal persistent health benefits even if some weight is regained

Study Summary:

10% Weight Loss Phase - Subject participation in the study will involve a series of metabolic tests before, at midpoint, and after undergoing a 10% weight loss program (with or without exercise training depending on group randomization). During this, subjects will be randomized into one of two different experimental groups:

1. Moderate Intensity Continuous Training (MICT) exercise group

2. No exercise (control) group

Follow-up Phase: After completing the metabolic testing post-weight loss, all study-related diet and exercise supervision will end and subjects will be free to make their own choices regarding diet and exercise/physical activity behavior. Subjects will then be asked to complete follow-up testing at 2-, 4- and 6- months post-weight loss.

Total involvement in the study for each subject will likely be about 10-13 months (4-7 months during weight loss phase, 6 months during follow-up phase).

Conditions

Obesity; Metabolic Disease; Metabolic Syndrome; Insulin Sensitivity; Insulin Resistance; Weight Loss

Study Design

• Allocation Method: RANDOMIZED
• Intervention Model: PARALLEL
• Primary Study Purpose: BASIC_SCIENCE
• Blinding Strategy: NONE

Study Groups

Moderate Intensity Continuous Training (MICT) exercise group

45 minutes of continuous steady-state exercise at 70% maximal heart rate throughout the 10% weight loss phase of the study

Group Type: EXPERIMENTAL

MICT Exercise

Intervention Type: BEHAVIORAL

Subjects randomized into this group will complete a moderate intensity continuous exercise 4 days/week.

No exercise (Control)

to remain sedentary (no planned physical exercise) throughout the duration of the 10% weight loss phase of the study

Group Type: EXPERIMENTAL

No Exercise (Control)

Intervention Type: BEHAVIORAL

Subjects randomized into this group will remain sedentary throughout the duration of the study.

Interventions

MICT Exercise

Subjects randomized into this group will complete a moderate intensity continuous exercise 4 days/week.

Intervention Type: BEHAVIORAL

No Exercise (Control)

Subjects randomized into this group will remain sedentary throughout the duration of the study.

Intervention Type: BEHAVIORAL

Eligibility Criteria

Inclusion Criteria

• Age: 18-40
• Body Mass Index: 30-40 kg/m2
• Weight stable (±3kg for greater than or equal to about 2 months)
• No regularly planned exercise/physical activity
• Women must have regularly occurring menses and must be premenopausal

Exclusion Criteria

• EKG abnormalities
• Evidence/history of cardiovascular disease, diabetes or other metabolic disease
• Medications known to affect lipid or glucose metabolism
• Pregnant or lactating
• Tobacco or e-cigarette use
• Prior experience of hypersensitivity to insulin, human albumin, and potassium chloride injection.
• Allergies/hypersensitivity to local anesthetics of the amide type (e.g., lidocaine)
• History of hyperkalemia or potential for developing hyperkalemia (including but not limited to taking drugs that may induce hyperkalemia such as cardiac glycosides or potassium sparing diuretics)

• Minimum Eligible Age: 18 Years
• Maximum Eligible Age: 40 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: Yes

Sponsors

University of Michigan

OTHER

Sponsor Role: lead

Responsible Party

Jeffrey F Horowitz

Professor of Movement Science and Director of the Substrate Metabolism Laboratory (SML) at the University of Michigan School of Kinesiology

Responsibility Role: PRINCIPAL_INVESTIGATOR

Principal Investigators

Jeffrey Horowitz, PhD

Role: PRINCIPAL_INVESTIGATOR

University of Michigan

Locations

University of Michigan

Ann Arbor, Michigan, United States

Site Status: RECRUITING

Countries

United States

Central Contacts

Suzette M Howton

Role: CONTACT

suzetter@med.umich.edu

734-647-9850

Facility Contacts

Suzette Howton

Role: primary

suzetter@med.umich.edu

7346479850

Other Identifiers

HUM00220220

Identifier Type: -

Identifier Source: org_study_id