NCT03074643

Utilizing Protein During Weight Loss to Impact Physical Function

Long-term Effects of Weight Loss and Supplemental Protein on Physical Function

• Status: Completed
• Phase: N/A
• Study type: Interventional
• Enrollment: 187 (actual)
• Sponsor: Wake Forest University Health Sciences · Academic / Other
• Sex: All
• Age: 65 Years – 85 Years
• Healthy volunteers: Not accepted

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

Interventions

Type	Name	Description
BEHAVIORAL	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).
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.
DIETARY_SUPPLEMENT	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.
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.
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.

Timeline

• Start date: 2017-05-03
• Primary completion: 2022-04-28
• Completion: 2022-04-28
• First posted: 2017-03-09
• Last updated: 2023-05-22
• Results posted: 2023-05-22

Locations

1 site across 1 country: United States