Metabolic Adaptations to Weight Loss With and Without Exercise

Not Applicable

Recruiting

• Conditions: Insulin Resistance; Obesity; Metabolic Syndrome; Weight Loss; Metabolic Disease; Insulin Sensitivity
• Interventions: Behavioral: MICT Exercise; Behavioral: No Exercise (Control)

• Registration Number: NCT05806801
• Lead Sponsor: University of Michigan

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).

Detailed Description

Not available

Study Timeline

• Study First Submitted: 2023-03-28
• Study First Submitted QC: 2023-03-28
• Study First Posted: 2023-04-10
• Study Start: 2023-07-19
• Status Verified: 2025-04
• Last Update Submitted: 2025-04-04
• Last Update Posted: 2025-04-08
• Primary Completion: 2027-08-01
• Study Completion: 2028-05-31

Recruitment & Eligibility

• Status: RECRUITING
• Sex: All
• Target Recruitment: 68

Inclusion Criteria

Not provided

Exclusion Criteria

Not provided

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
Moderate Intensity Continuous Training (MICT) exercise group	MICT Exercise	45 minutes of continuous steady-state exercise at 70% maximal heart rate throughout the 10% weight loss phase of the study
No exercise (Control)	No Exercise (Control)	to remain sedentary (no planned physical exercise) throughout the duration of the 10% weight loss phase of the study

Primary Outcome Measures

Name	Time	Method
Adipose tissue fibrosis	30 minutes	measured histologically using Sirus Red Staining, quantified using ImageJ software
Insulin sensitivity	2 hours	a hyperinsulinemic-euglycemic clamp will be used to quantify peripheral insulin sensitivity
Fatty acid turnover	2 hours	stable isotope tracer infusion methods will be used to assess fatty acid turnover
Adipose tissue capillarization	30 minutes	measured immunohistochemically using an antibody for CD31, quantified using ImageJ software

Secondary Outcome Measures

Name	Time	Method
Body weight change	6 months	Change in body weight will be assessed 6 months after completing the 10% weight loss intervention
Body fat mass	30 minutes	Body fat mass will be measured by Dual Energy X-ray Absorptiometry (DEXA)
Oral Glucose Tolerance Test (OGTT)	2 hours	A test in which glucose is given and blood samples taken afterward to determine how quickly it is cleared from the blood will be completed at each clinical visit appointment

Trial Locations

Locations (1)

University of Michigan; 🇺🇸 Ann Arbor, Michigan, United States