Optimizing Adaptive Intensive Behavioral Therapy for Obesity During the Transition to Older Adulthood

Optimizing Adaptive Intensive Behavioral Therapy for Obesity During the Transition to Older Adulthood: A Sequential Multiple Assignment Randomized Trial

To test adaptive intensive behavioral therapy strategies comprising dietary patterns with varying amounts of protein and including supplemental protein or resistance exercise training for promoting weight loss and attenuating lean mass loss in adults aged 50-75 with obesity.

Study Overview

• Status: Not yet recruiting
• Conditions: Sarcopenia; Obesity & Overweight
• Intervention / Treatment: Behavioral: High Protein Diet Counceling; Behavioral: Protein Supplement; Behavioral: Supervised Exercise; Behavioral: Standard Protein Diet Counceling

Detailed Description

This Sequential Multiple Assignment Randomized Trial (SMART) seeks to identify the optimal initial dietary strategy (high vs. standard protein diets) and as-needed augmentation strategy (protein supplementation vs. supervised resistance exercise training) for behavioral weight loss in adults aged 50-75. Augmentation strategies will only be used for participants who do not achieve at least 3% weight loss and/or those who lose more than 1.5 kg of fat free mass (i.e., Non-Responders) after 8 weeks of group-based behavioral obesity treatment. Protein supplements and supervised resistance exercise training will be provided at no-cost to participants for weeks 9-16 of the study. Responders (i.e., achieving at least 3% weight loss and less than 1.5 kg loss of fat free mass) will continue with their initial high protein or standard protein diet assignment for the remainder of the trial. This SMART will enroll 250 adults aged 50-75 years with a BMI of at least 30 kg/m2. All participants will receive 1 year of behavioral obesity treatment including 16 weeks of weekly group-based treatment (active weight loss phase) followed by 36 weeks of monthly group sessions to promote continued engagement in dietary and exercise behaviors and long-term weight loss maintenance. The behavioral intervention will be delivered via Zoom. Data collection will occur at the University of Alabama at Birmingham and 5 study visits will be scheduled including: screening (to determine eligibility), prior to starting the weight loss intervention (baseline), and at weeks 8, 16, and 52.

• Study Type: Interventional
• Enrollment (Estimated): 250
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United States
  • Alabama
    • Birmingham, Alabama, United States, 35233
      • University of Alabama at Birmingham
      • Principal Investigator: Drew Sayer, MD

Participation Criteria

Eligibility Criteria

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

Description

Inclusion Criteria:

• Male or female sex
• all racial and ethnic groups
• BMI: 30-50 kg/m2
• age 50-75 years
• postmenopausal status for ≥1 y if female sex

Exclusion Criteria:

• <3 months stable use of other medications affecting body weight or appetite
• >450 pounds (due to weight limitations of the DXA)
• indication or previous diagnosis of sarcopenia
• existing kidney disease
• current binge eating disorder, anorexia, or bulimia
• untreated hyper- or hypothyroidism, cancer (except basal cell), gastrointestinal disorders affecting food intake or nutrient absorption; any other medical condition, as determined by the study physician, precluding a HP diet and/or daily exercise

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Sequential Assignment
• Masking: Double

Number of Arms

6

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: High Protein Diet Only; Enrollment in State of Slim (SOS) weight loss program with a high protein diet. This arm includes participants identified as responders to the high protein diet counseling in stage 1 at the week 8 assessment.	Behavioral: High Protein Diet Counceling; 16 week group-based weight loss program with counseling to consume a high protein diet. Approximate macronutrient distributions (carbohydrate:protein:fat) will be 32%:40%:28%.
Active Comparator: High Protein Diet + Supplement; Enrollment in State of Slim (SOS) weight loss program with a high protein diet. Participants identified as non-responders at the week 8 assessment will receive protein supplements to augment their intervention plan.	Behavioral: High Protein Diet Counceling; 16 week group-based weight loss program with counseling to consume a high protein diet. Approximate macronutrient distributions (carbohydrate:protein:fat) will be 32%:40%:28%.; Behavioral: Protein Supplement; Non-responders from either initial randomized group assigned to this intervention receive twice daily protein supplements.
Active Comparator: High Protein Diet + Supervised Exercise; Enrollment in State of Slim (SOS) weight loss program with a high protein diet. Participants identified as non-responders at the week 8 assessment will receive supervised resistance training sessions to augment their intervention plan.	Behavioral: High Protein Diet Counceling; 16 week group-based weight loss program with counseling to consume a high protein diet. Approximate macronutrient distributions (carbohydrate:protein:fat) will be 32%:40%:28%.; Behavioral: Supervised Exercise; Non-responders from either initial randomized group assigned to this intervention receive twice weekly small-group supervised resistance exercise training sessions.
Active Comparator: Standard Protein Diet Only; Enrollment in State of Slim (SOS) weight loss program with a standard protein diet. This arm includes participants identified as responders to the standard protein diet counseling in stage 1 at the week 8 assessment.	Behavioral: Standard Protein Diet Counceling; 16 week group-based weight loss program with counseling to consume a standard protein diet. Approximate macronutrient distributions (carbohydrate:protein:fat) will be 53%:20%:27%.
Active Comparator: Standard Protein Diet + Supplement; Enrollment in State of Slim (SOS) weight loss program with a standard protein diet. Participants identified as non-responders at the week 8 assessment will receive protein supplements to augment their intervention plan.	Behavioral: Protein Supplement; Non-responders from either initial randomized group assigned to this intervention receive twice daily protein supplements.; Behavioral: Standard Protein Diet Counceling; 16 week group-based weight loss program with counseling to consume a standard protein diet. Approximate macronutrient distributions (carbohydrate:protein:fat) will be 53%:20%:27%.
Active Comparator: Standard Protein Diet + Supervised Exercise; Enrollment in State of Slim (SOS) weight loss program with a standard protein diet. Participants identified as non-responders at the week 8 assessment will receive supervised resistance training sessions to augment their intervention plan.	Behavioral: Supervised Exercise; Non-responders from either initial randomized group assigned to this intervention receive twice weekly small-group supervised resistance exercise training sessions.; Behavioral: Standard Protein Diet Counceling; 16 week group-based weight loss program with counseling to consume a standard protein diet. Approximate macronutrient distributions (carbohydrate:protein:fat) will be 53%:20%:27%.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in Body Weight	Participants will be weighed at baseline through 52 weeks	Baseline, 8 weeks, 16 weeks, 52 weeks
Change in Fat Free Mass	Participants will be scanned via DXA scan to measure overall fat free body mass	Baseline, 8 weeks, 16 weeks, 52 weeks

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in Fat Mass	Participants will be scanned via DXA scan to measure overall fat mass	Baseline, 8 weeks, 16 weeks, 52 weeks
Change in Fasting Glucose	Participants will have a blood draw to check fasting blood sugar levels	Baseline, 8 weeks, 16 weeks, 52 weeks
Change in Fasting Insulin	Participants will have a blood draw to check fasting insulin levels	Baseline, 8 weeks, 16 weeks, 52 weeks
Change in Fasting Hemoglobin A1C	Participants will have a blood draw to check fasting A1C levels	Baseline, 8 weeks, 16 weeks, 52 weeks
Change in Fasting LDL-cholesterol	Participants will have a blood draw to check fasting LDL-cholesterol levels	Baseline, 8 weeks, 16 weeks, 52 weeks
Change in Fasting HDL-cholesterol	Participants will have a blood draw to check fasting HDL-cholesterol levels	Baseline, 8 weeks, 16 weeks, 52 weeks
Change in Fasting Total Cholesterol	Participants will have a blood draw to check fasting total cholesterol levels	Baseline, 8 weeks, 16 weeks, 52 weeks
Change in Fasting Total Triglycerides	Participants will have a blood draw to check fasting triglyceride levels	Baseline, 8 weeks, 16 weeks, 52 weeks
Change in Blood Pressure	Participants will have a blood pressure check at each appointment	Baseline, 8 weeks, 16 weeks, 52 weeks
Change in Hand Grip Strength	Participants will have hand grip strength via the Jamar dynamometer, a tool for assessing and monitoring patients' hand strength. Measurements are based on a scale of 0-90 kilograms of force, where higher numbers indicate more strength.	Baseline, 8 weeks, 16 weeks, 52 weeks
Change in Lower Extremity Strength	Participants will be assessed using the Short Physical Performance Battery (SPPB). The SPPB is a commonly-used assessment of lower extremity function in aging adults and used a combined score comprising tests of balance, gait speed, and the chair stand test. Key Components and Scoring (0-12 points total): Standing Balance: Evaluates three stances (side-by-side, semi-tandem, tandem) held for 10 seconds each, scored up to 4 points. Gait Speed: Measures the time taken to walk 3 or 4 meters at a normal pace, scored up to 4 points. Chair Stands: Measures the time taken to rise from a chair five times without using arms, scored up to 4 points. Interpretation and Cut-off Scores: Total Score 0-6: Indicates low performance and high risk for functional decline. Total Score 7-9: Moderate performance. Total Score 10-12: High performance.	Baseline, 8 weeks, 16 weeks, 52 weeks

Collaborators and Investigators

• Sponsor: University of Alabama at Birmingham
• Investigators: Principal Investigator: Drew Sayer, MD, University of Alabama at Birmingham

Study record dates

Study Major Dates

• Study Start (Estimated): July 1, 2026
• Primary Completion (Estimated): June 30, 2031
• Study Completion (Estimated): June 30, 2031

Study Registration Dates

• First Submitted: February 25, 2026
• First Submitted That Met QC Criteria: February 25, 2026
• First Posted (Actual): March 3, 2026

Study Record Updates

• Last Update Posted (Actual): April 29, 2026
• Last Update Submitted That Met QC Criteria: April 23, 2026
• Last Verified: April 1, 2026

More Information

Terms related to this study

• Keywords: Obesity; Sarcopenia
• Additional Relevant MeSH Terms: Neurologic Manifestations; Nervous System Diseases; Neuromuscular Manifestations; Nutrition Disorders; Pathological Conditions, Anatomical; Overnutrition; Body Weight; Muscular Atrophy; Atrophy; Pathological Conditions, Signs and Symptoms; Nutritional and Metabolic Diseases; Signs and Symptoms; Overweight; Obesity; Sarcopenia
• Other Study ID Numbers: IRB-300016298

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES
• IPD Plan Description: At the time of publication(s) related to this trial, a fully de-identified dataset including individual participant data will be made available so that data analysis can be replicated by other investigators. This dataset will be freely available for download as supplemental material to manuscript(s) submitted to PubMed Central.
• IPD Sharing Time Frame: IPD and supporting information will be available at the time of publication of manuscripts associated with this trial.
• IPD Sharing Access Criteria: Freely available for download from PubMed Central as supplemental material to associated manuscripts.
• IPD Sharing Supporting Information Type: STUDY_PROTOCOL; SAP; ANALYTIC_CODE

Drug and device information, study documents

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