Utilizing Protein During Weight Loss to Impact Physical Function

NCT ID: NCT03074643

Last Updated: 2023-05-22

Basic Information

• Recruitment Status: COMPLETED
• Clinical Phase: NA
• Total Enrollment: 187 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2017-05-03
• Study Completion Date: 2022-04-28

Brief Summary

This study will evaluate the effects of diet composition (i.e., amount of protein and carbohydrate) during a 6-month weight loss intervention and 12-months of follow-up on physical function, muscle mass, and weight loss maintenance in obese older adults. Participants will receive either a protein or carbohydrate supplement along with a behavioral weight loss intervention.

Detailed Description

The study will use a 3-group design in 225 obese (BMI 27-45 kg/m2), older (65-85 years) men and women at risk for disability (eSPPB <2.5) who will undergo a 6-month weight loss intervention followed by a 12-month follow-up phase to test the overall hypothesis that a higher protein (1.2 g/kg body wt/d) / lower carbohydrate (CHO) diet during a 6-month weight loss intervention improves physical function compared with an isocaloric lower protein (the current Recommended Dietary Allowance (RDA), 0.8 g/kg body wt/d) / higher CHO diet, and whether continuing a higher protein / lower CHO diet for 12-months following weight loss will result in better maintenance of improved physical function. All participants will undergo a 6-month weight loss intervention involving caloric restriction and supervised exercise followed by 12 months of follow-up with randomization to one of three groups (n=75/group): 1) Lower protein / higher CHO diet for the 6-month weight loss phase only (RecProt); 2) Higher protein / lower CHO diet for the 6-month weight loss phase only (6-mo HiProt); or 3) Higher protein / lower CHO diet for the 6-month weight loss and 12-month follow-up phases (18-mo HiProt). Physical function (primary aim) will be assessed by the expanded Short Physical Performance Battery (primary outcome) and lower extremity muscle strength at baseline, 6-, 12- and 18-months. Weight loss maintenance and body composition (secondary aim) will be assessed by dual-energy X-ray absorptiometry (DXA) and computed tomography (CT) at baseline, 6- and 18-months. Bone mineral density (DXA) and cardiometabolic risk factors will also be measured at baseline, 6- and 18-months.

Conditions

Obesity; Weight Loss; Diet Modification; Aging; Weight Change, Body; Dietary Habits

Study Design

• Allocation Method: RANDOMIZED
• Intervention Model: PARALLEL
• Primary Study Purpose: TREATMENT
• Blinding Strategy: TRIPLE

Study Groups

RecProt

Lower protein / higher CHO diet for the 6-month weight loss phase. Exercise intervention months 0-6. Weight loss intervention months 0-6. Carbohydrate supplement for months 0-6 (blinded). Follow-up months 7-18.

Group Type: PLACEBO_COMPARATOR

Weight loss intervention months 0-6

Intervention Type: BEHAVIORAL

All participants will undergo a dietary weight loss intervention designed to elicit behavioral changes leading to decreased caloric intake sufficient to yield a \~10% loss of initial body mass. The weight loss intervention will incorporate nutrition education (via group and individual meetings with the study dietitian), self-monitoring skills, cognitive-behavioral strategies for promoting lifestyle behavior modifications, and planned meals. Behavioral and educational group and individual sessions will be held weekly in a 3:1 ratio (3 group and 1 individual session per month).

Exercise intervention months 0-6

Intervention Type: BEHAVIORAL

All participants will be expected to participate in a supervised, center-based exercise program involving moderate-intensity aerobic exercise (e.g., treadmill walking) 3 days/wk during the 6-month weight loss intervention in accordance with the American Heart Association and the American College of Sports Medicine physical activity recommendations for older adults.

Carbohydrate supplement for months 0-6

Intervention Type: DIETARY_SUPPLEMENT

Participants in the lower protein / higher CHO diet group (RecProt) will be provided a carbohydrate supplement (\~50 g of carbohydrate and 220 calories) to consume daily during the 6 month weight loss intervention.

6-mon HiProt

Higher protein / lower CHO diet for the 6-month weight loss phase. Exercise intervention months 0-6. Weight loss intervention months 0-6. Protein supplement for months 0-6 (blinded). Follow-up months 7-18.

Group Type: ACTIVE_COMPARATOR

Weight loss intervention months 0-6

Intervention Type: BEHAVIORAL

All participants will undergo a dietary weight loss intervention designed to elicit behavioral changes leading to decreased caloric intake sufficient to yield a \~10% loss of initial body mass. The weight loss intervention will incorporate nutrition education (via group and individual meetings with the study dietitian), self-monitoring skills, cognitive-behavioral strategies for promoting lifestyle behavior modifications, and planned meals. Behavioral and educational group and individual sessions will be held weekly in a 3:1 ratio (3 group and 1 individual session per month).

Exercise intervention months 0-6

Intervention Type: BEHAVIORAL

All participants will be expected to participate in a supervised, center-based exercise program involving moderate-intensity aerobic exercise (e.g., treadmill walking) 3 days/wk during the 6-month weight loss intervention in accordance with the American Heart Association and the American College of Sports Medicine physical activity recommendations for older adults.

Protein supplement for months 0-6

Intervention Type: DIETARY_SUPPLEMENT

Participants in the higher protein / lower CHO diet groups (6-mon HiProt and 18-mon HiProt) will be provided a protein supplement (\~50 g of protein and 220 calories) to consume daily during the 6 month weight loss intervention.

18-mon HiProt

Higher protein / lower CHO diet for the 6-month weight loss and 12-month follow-up phases.

Exercise intervention months 0-6. Weight loss intervention months 0-6. Protein supplement for months 0-6 (blinded). Protein supplement for follow-up months 7-18.

Group Type: ACTIVE_COMPARATOR

Weight loss intervention months 0-6

Intervention Type: BEHAVIORAL

All participants will undergo a dietary weight loss intervention designed to elicit behavioral changes leading to decreased caloric intake sufficient to yield a \~10% loss of initial body mass. The weight loss intervention will incorporate nutrition education (via group and individual meetings with the study dietitian), self-monitoring skills, cognitive-behavioral strategies for promoting lifestyle behavior modifications, and planned meals. Behavioral and educational group and individual sessions will be held weekly in a 3:1 ratio (3 group and 1 individual session per month).

Exercise intervention months 0-6

Intervention Type: BEHAVIORAL

All participants will be expected to participate in a supervised, center-based exercise program involving moderate-intensity aerobic exercise (e.g., treadmill walking) 3 days/wk during the 6-month weight loss intervention in accordance with the American Heart Association and the American College of Sports Medicine physical activity recommendations for older adults.

Protein supplement for months 0-6

Intervention Type: DIETARY_SUPPLEMENT

Participants in the higher protein / lower CHO diet groups (6-mon HiProt and 18-mon HiProt) will be provided a protein supplement (\~50 g of protein and 220 calories) to consume daily during the 6 month weight loss intervention.

Protein supplement for follow-up months 7-18

Intervention Type: DIETARY_SUPPLEMENT

Participants in the higher protein / lower CHO diet (18-mon HiProt) will be provided a protein supplement (\~50 g of protein and 220 calories) to consume daily during the 12-month follow-up.

Interventions

Weight loss intervention months 0-6

All participants will undergo a dietary weight loss intervention designed to elicit behavioral changes leading to decreased caloric intake sufficient to yield a \~10% loss of initial body mass. The weight loss intervention will incorporate nutrition education (via group and individual meetings with the study dietitian), self-monitoring skills, cognitive-behavioral strategies for promoting lifestyle behavior modifications, and planned meals. Behavioral and educational group and individual sessions will be held weekly in a 3:1 ratio (3 group and 1 individual session per month).

Intervention Type: BEHAVIORAL

Exercise intervention months 0-6

All participants will be expected to participate in a supervised, center-based exercise program involving moderate-intensity aerobic exercise (e.g., treadmill walking) 3 days/wk during the 6-month weight loss intervention in accordance with the American Heart Association and the American College of Sports Medicine physical activity recommendations for older adults.

Intervention Type: BEHAVIORAL

Carbohydrate supplement for months 0-6

Participants in the lower protein / higher CHO diet group (RecProt) will be provided a carbohydrate supplement (\~50 g of carbohydrate and 220 calories) to consume daily during the 6 month weight loss intervention.

Intervention Type: DIETARY_SUPPLEMENT

Protein supplement for months 0-6

Participants in the higher protein / lower CHO diet groups (6-mon HiProt and 18-mon HiProt) will be provided a protein supplement (\~50 g of protein and 220 calories) to consume daily during the 6 month weight loss intervention.

Intervention Type: DIETARY_SUPPLEMENT

Protein supplement for follow-up months 7-18

Participants in the higher protein / lower CHO diet (18-mon HiProt) will be provided a protein supplement (\~50 g of protein and 220 calories) to consume daily during the 12-month follow-up.

Intervention Type: DIETARY_SUPPLEMENT

Eligibility Criteria

Inclusion Criteria

• 65-85 years
• BMI: 27-45 kg/m2
• No regular resistance training and/or aerobic exercise (>20 mins/d) for past 6 months
• eSPPB <2.5
• No contraindications for safe and optimal participation in exercise training
• Approved for participation by Medical Director (Dr. Lyles)
• Willing to provide informed consent
• Agree to all study procedures and assessments
• Willing to consume protein/CHO supplements for up to 18 months
• Able to provide own transportation to study visits and intervention sessions

Exclusion Criteria

• Weight loss (≥5%) in past 6 months
• Dependent on cane or walker
• Cognitive impairment (MoCA score <22)
• Severe arthritis, or other musculoskeletal disorder
• Joint replacement or other orthopedic surgery in past 6 months
• Uncontrolled resting hypertension (>160/90 mmHg);
• Insulin-dependent or uncontrolled diabetes (HbA1c ≥8%)
• Current or recent past (within 1 year) severe symptomatic heart disease, uncontrolled angina, stroke, chronic respiratory disease requiring oxygen; uncontrolled endocrine/metabolic disease; neurological or hematological disease; cancer requiring treatment in past year, except non-melanoma skin cancers; liver or renal disease; or clinically evident edema
• Unstable, severe depression
• Serious conduction disorder, uncontrolled arrhythmia, or new Q waves or ST-segment depressions (>3 mm at rest or ≥2 mm with exercise)
• Abnormal kidney function (eGFR <30 based on serum creatinine, age, gender, and race)
• Anemia (Hb<13 g/dL in men; <12 g/dL in women)
• Drug abuse or excessive alcohol use (>7 drinks/week women; >14 drinks/week men)
• Use of any tobacco or nicotine products in the past year
• Osteoporosis (T-score < -2.5 on hip or spine scan)
• Regular use of growth/steroid hormones, sex steroids or corticosteroids, osteoporosis medication, or protein supplements
• Weight loss medications or procedures
• Current participation in another intervention study

• Minimum Eligible Age: 65 Years
• Maximum Eligible Age: 85 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: No

Sponsors

National Institute on Aging (NIA)

NIH

Sponsor Role: collaborator

Wake Forest University Health Sciences

OTHER

Sponsor Role: lead

Responsible Party

Responsibility Role: SPONSOR

Principal Investigators

Denise Houston, PhD

Role: PRINCIPAL_INVESTIGATOR

Wake Forest University Health Sciences

Locations

Geriatric Research Center at Wake Forest Baptist Health

Winston-Salem, North Carolina, United States

Countries

United States

Provided Documents

Document Type: Study Protocol and Statistical Analysis Plan

View Document

Document Type: Informed Consent Form

View Document

Other Identifiers

R01AG050656

Identifier Type: NIH

Identifier Source: secondary_id

View Link

IRB00038668

Identifier Type: -

Identifier Source: org_study_id