Menopause, Obesity, Osteoporosis, Sarcopenia
Conditions
Brief summary
The purpose of this study is to determine whether consuming additional protein during calorie restriction induced weight loss has beneficial or harmful effects on multi-organ (liver, muscle, adipose tissue) insulin sensitivity, colonocyte proliferation rates, the gut microbiome, muscle mass and function, and bone mineral density in obese, postmenopausal women.
Interventions
BEHAVIORALWeight loss with normal protein intake
Goal of 8 to 10% weight loss while consuming the recommended daily allowance of protein (i.e, 0.8 grams of protein per kg body weight per day).
BEHAVIORALWeight loss with protein supplementation
Goal of 8 to 10% weight loss while consuming 150% of the recommended daily allowance of protein (i.e., 1.2 grams of protein per kg body weight per day).
Sponsors
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
Washington University School of Medicine
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
NONE
Eligibility
Sex/Gender
FEMALE
Age
50 Years to 65 Years
Healthy volunteers
Yes
Inclusion criteria
* Obese with body mass index (BMI) between 30 and 50 kg/m2 * Postmenopausal * Sedentary (i.e., less than 1.5 hours of exercise per week)
Exclusion criteria
* Individuals with diabetes and/or uncontrolled hypertension * Individuals with hepatitis B and/or C * Individuals who smoke * Individuals with an allergy to whey protein
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Change in muscle volume | Baseline and at 10% weight loss in calorie restriction groups and ~6 to 7 months in the weight maintenance group | Thigh muscle volume will be measured by magnetic resonance imaging (MRI) |
| Change in muscle strength | Baseline and at 10% weight loss in calorie restriction groups and ~6 to 7 months in the weight maintenance group | Muscle strength will be evaluated by administering maximum one repetition strength and isokinetic strength tests. |
| Changes in bone mineral density and bone mineral content | Baseline and at 10% weight loss in calorie restriction groups and ~6 to 7 months in the weight maintenance group | Total bone mass and total body and regional bone mineral density will be evaluated by using dual X-ray energy absorptiometry (DXA). |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Change in cell proliferation (growth) rates in the colon | Baseline and at 10% weight loss in calorie restriction groups and ~6 to 7 months in the weight maintenance group | Colon cell proliferation rates will be determined using stable isotope labelled tracer methods in conjunction with sigmoid colon biopsy samples |
| Change in insulin sensitivity | Baseline and at 10% weight loss in calorie restriction groups and ~6 to 7 months in the weight maintenance group | Insulin sensitivity (glucose rate of disappearance \[Rd\] during a hyperinsulinemic-euglycemic clamp procedure) will be evaluated in a subset of 10 participants per group because power analysis has determined that this number is sufficient to detect a 25% difference between groups assuming 80% power, an alpha value of 0.05 and an average baseline insulin-stimulated glucose Rd of 2,590 ± 492 µmol/min, the average ± SD insulin stimulated glucose Rd the investigators have measured during the past 20 y in obese subjects. In the investigators' experience (Kirk et al., 2009 and Magkos et al., 2016), the weight loss induced increase in insulin stimulated glucose Rd is \ 50%. |
| Determine the acute effect of whey protein ingestion on muscle protein metabolism | Prior to starting the weight loss or maintenance intervention | Rates of muscle protein synthesis, breakdown and net protein balance will be assessed using stable isotope labeled tracer methods during postabsorptive conditions and during insulin infusion with or without whey protein ingestion |
| Determine the acute effect of whey protein ingestion on skeletal muscle insulin sensitivity | Prior to starting the weight loss or maintenance intervention | Insulin sensitivity will be evaluated using the hyperinsulinemic-euglycemic clamp procedure in conjunction with stable isotope labeled tracer infusions |
| Change in muscle protein metabolism | Baseline and at 5% weight loss in the calorie restriction groups and after ~3 months in the weight maintenance group | Rates of muscle protein synthesis, breakdown and net protein balance will be assessed during postabsorptive conditions and when insulin and/or amino acid concentrations are elevated. |
| Change in bacterial populations found in the stool | Baseline and at 10% weight loss in calorie restriction groups and ~6 to 7 months in the weight maintenance group | — |
Countries
United States
Outcome results
None listed