Lifestyle Intervention to Improve Muscle Function in Older Adults

The goal of this randomized controlled two-arm trial is to determine the effect of a diet and exercise intervention for 12 weeks on body composition, muscle function, and energy balance in 80 adults aged 50 years and over with obesity and insulin resistance. The main questions the trial aims to answer are: Will 12 weeks of a structured nutrition plan + exercise reduce fat mass, improve muscle function, and increase energy deficit compared to the usual diet + exercise. The hypothesis is that 12 weeks of a structured nutrition plan + exercise will reduce fat mass, improve muscle function, and produce greater energy deficit than the usual diet + exercise. Participants will be provided with all meals for 12 weeks and will exercise at the Center under supervision three times each week. Pre and post-intervention, body composition, physical function, and energy deficit will be measured.

Study Overview

• Status: Not yet recruiting
• Conditions: Body Composition; Physical Function; Energy Balance
• Intervention / Treatment: Behavioral: Structured nutrition plan + exercise; Other: Typical or usual diet + exercise

Detailed Description

In the United States nearly one third of adults over 60 years of age have sarcopenic obesity which encompasses the combined effect of muscle impairment and obesity. A strategy that addresses the combined effect of muscle impairment and obesity while modulating muscle mass and composition is an unanswered challenge. This 12-week study will evaluate the effects of a structured nutrition plan combined with an exercise program on body fat and muscle mass, lower-extremity function (Short Physical Performance Battery), muscle strength (handgrip and knee strength), and daily caloric intake. The study will enroll adults aged 50 years and older with obesity (body mass index ≥ 30 kg/m²) and insulin resistance as indicated by a homeostasis model assessment of insulin resistance (HOMA-IR) score ≥ 3. Subjects will be randomly allocated to receive the structured nutrition plan and exercise intervention or to their usual diet and exercise in equal numbers (40 per group). The study will enrich our understanding of the physiological adaptations necessary for effective lifestyle interventions to improve muscle function.

• Study Type: Interventional
• Enrollment (Estimated): 80
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Candida J Rebello, PhD, RD; Phone Number: 12257633159; Email: Candida.Rebello@pbrc.edu
• Study Contact Backup: Name: Reilly Roberts A Project Manager, MS; Phone Number: 225-763-2854; Email: candidajoan@hotmail.com

Study Locations

• United States
  • Louisiana
    • Baton Rouge, Louisiana, United States, 70808
      • Pennington Biomedical Research Center
      • Contact: Candida J Rebello, PhD, RD; Phone Number: 225-763-3159; Email: Candida.Rebello@pbrc.edu
      • Contact: Reilly Roberts A Project Manager, MS; Phone Number: 225-763-2854; Email: Reilly.Roberts@pbrc.edu

Participation Criteria

Eligibility Criteria

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

Description

Inclusion Criteria:

1. Age > 50 years.
2. Body mass index (BMI) ≥ 30 kg/m2.
3. Homeostatic model assessment of insulin resistance ≥ 3.
4. Mini-Mental State Examination (MMSE) > 25.
5. Geriatric Depression Scale-15 (GDS-15) < 9.
6. Sedentary (less than 90 minutes/week of moderate to vigorous activity).
7. Ability to provide written informed consent.

Exclusion Criteria:

1. Diagnosis of cancer (received within five years) or diabetes (type 1 and 2), or significant musculoskeletal, or cardiovascular, or hepatic, or renal, disease or dysfunction.
2. Clinically significant gastrointestinal malabsorption syndromes such as chronic diarrhea, celiac disease, or clinically significant abnormal laboratory markers.
3. Fluctuation in body weight > 3 kg in the preceding two months
4. Condition that impedes testing of the study hypothesis or makes it unsafe to exercise or consume the study foods.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Triple

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Structured nutrition plan + exercise; Intervention: Participants receive a structured nutrition plan, and exercise under supervision.	Behavioral: Structured nutrition plan + exercise; Participants will receive a structured nutrition plan. The exercise intervention will be the same in both groups.
Active Comparator: Typical or usual diet + exercise; Participants receive a typical or usual diet, and exercise under supervision	Other: Typical or usual diet + exercise; Participants will receive a diet representing the usual diet in this population. The exercise intervention will be the same in both groups.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Fat mass	Fat mass measured by dual X-ray absorptiometry	Change from baseline to 12 weeks

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Skeletal muscle mass	Skeletal muscle mass will be measured by the creatine methyl D-3 dilution method	Change in from baseline to 12 weeks
Short physical performance battery	A test of physical function	Change from baseline to 12 weeks
Hand-grip strength	Hand grip strength will be measured using a hand dynamometer	Change from baseline to 12 weeks
Knee strength	Knee strength will be measured quantified using Biodex dynamometry	Change from baseline to12 weeks
Energy stores	Change in energy stores/day (kcal) determined from measures of body composition using the energy balance method	12 weeks
Hormonal regulation of energy balance	Blood concentrations of glucagon-like peptide 1	Change from baseline to 12 weeks
Hormonal regulation of energy balance	Blood concentrations of gastric inhibitory peptide	Change from baseline to 12 weeks
Hormonal regulation of energy balance	Blood concentrations of cortisol	Change from baseline to 12 weeks
Hormonal regulation of energy balance	Blood concentrations of leptin	Change from baseline to 12 weeks
Cardiorespiratory fitness	VO2max	Change in VO2max from baseline to 12 weeks

Collaborators and Investigators

• Sponsor: Pennington Biomedical Research Center
• Collaborators: National Institute on Aging (NIA)
• Investigators: Principal Investigator: Candida J Rebello, PhD, RD, Pennington Biomedical Research Center

Study record dates

Study Major Dates

• Study Start (Estimated): June 1, 2026
• Primary Completion (Estimated): December 1, 2030
• Study Completion (Estimated): December 1, 2030

Study Registration Dates

• First Submitted: May 8, 2026
• First Submitted That Met QC Criteria: May 14, 2026
• First Posted (Actual): May 20, 2026

Study Record Updates

• Last Update Posted (Actual): May 20, 2026
• Last Update Submitted That Met QC Criteria: May 14, 2026
• Last Verified: May 1, 2026

More Information

Terms related to this study

• Keywords: muscle mass; physical function; Fat mass; energy deficit
• Additional Relevant MeSH Terms: Motor Activity; Movement; Musculoskeletal Physiological Phenomena; Musculoskeletal and Neural Physiological Phenomena; Exercise
• Other Study ID Numbers: PBRC-2025-060; 1R01AG092725-01A1 (U.S. NIH Grant/Contract)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO
• IPD Plan Description: At this time, we do not have plans to share IPD. We may consider it after the study results have been publicly disseminated

Drug and device information, study documents

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