Effect of Caloric Restriction and Protein Intake on Metabolism and Anabolic Sensitivity
- Conditions
- StarvationWeight Loss
- Interventions
- Other: Caloric RestrictionOther: ProteinOther: ExerciseDietary Supplement: Calcium and Vitamin DOther: Maltodextrin
- Registration Number
- NCT02945410
- Lead Sponsor
- University of Nebraska Lincoln
- Brief Summary
The purpose of this study is to determine if an increased protein intake can attenuate the suppression of metabolic and anabolic hormones during caloric restriction
- Detailed Description
1. Preliminary testing
Prior to the study start, participants will be weighed and body composition will be determined using calipermetry (7 sites) and bioelectrical impedance. Peak oxygen uptake (VO2peak) will be assessed using an incremental exercise test on a bicycle ergometer.
2. Randomization
Participants will proceed through each of the following conditions lasting 5 days:
CR-LP: Participants will be restricted to 30 kcal/kg FFM/day and protein intake will be low (0.8 g/kg BW/day).
CR-HP: Participants will be restricted to 30 kcal/kg FFM/day and protein intake will be high (1.7 g/kg BW/day).
CON: Participants will be in energy balance and consume 1.7 g protein/kg BW/day.
3. Diet Prescription
Dietary energy intake will be controlled using clinical products and maltodextrin to meet target energy intakes. Participants will received calcium and Vitamin D supplementation throughout the study.
4. Exercise Prescription
During all conditions, participants will conduct daily supervised exercise on a bicycle ergometer at an exercise intensity of 60% VO2peak. Exercise duration will be adjusted individually such that exercise energy expenditure will amount to 15 kcal/kg FFM/day. Additional exercise and intense physical activity will be prohibited.
5. Assessments
The following assessments will be conducted prior to the start of each condition as well as upon completion of each condition: body weight and composition (impedance), fasting blood draw for assessment of metabolic and anabolic hormones, resting metabolic rate, aerobic fitness (VO2peak), and questionnaires.
6. Washout
Once a participant has completed a study condition, participant will be allowed a washout of at least 14 days to allow protein balance to return to baseline (Hoffer \& Forse, 1990). During this time, participants will resume their regular diet and physical activity.
Recruitment & Eligibility
- Status
- COMPLETED
- Sex
- Male
- Target Recruitment
- 20
- 4 hours/week of purposeful aerobic exercise over the last 3 months
- Body mass index: 19-25 kg/m2
- < 15% body fat
- Cardiovascular disease risk factors that would result in greater than low risk
- Smoking
- Type I, type II diabetes, or history of high fasting glucose;
- History of high blood pressure and/or use of medication for hypertension;
- History of Dyslipidemia, or on lipid-lowering medication;
- Underlying health condition and/or use of medication that could interfere with any of our study outcomes.
- History or current diagnosis of a clinical eating disorder
- Failure to adhere to study protocol
Study & Design
- Study Type
- INTERVENTIONAL
- Study Design
- CROSSOVER
- Arm && Interventions
Group Intervention Description Caloric Restriction and High Protein Caloric Restriction Participants will be calorie restricted to 30 kcal/kg FFM/day and consume 1.7 g protein/kg BW/day. Caloric Restriction and High Protein Exercise Participants will be calorie restricted to 30 kcal/kg FFM/day and consume 1.7 g protein/kg BW/day. Caloric Restriction and High Protein Calcium and Vitamin D Participants will be calorie restricted to 30 kcal/kg FFM/day and consume 1.7 g protein/kg BW/day. Caloric Restriction and Normal Protein Calcium and Vitamin D Participants will be calorie restricted to 30 kcal/kg FFM/day and consume 0.8 g protein/kg BW/day. Caloric Restriction and Normal Protein Maltodextrin Participants will be calorie restricted to 30 kcal/kg FFM/day and consume 0.8 g protein/kg BW/day. Caloric Restriction and Normal Protein Exercise Participants will be calorie restricted to 30 kcal/kg FFM/day and consume 0.8 g protein/kg BW/day. Energy Balance Exercise Participants will be in energy balance and consume 1.7 g protein/kg BW/day. Energy Balance Protein Participants will be in energy balance and consume 1.7 g protein/kg BW/day. Energy Balance Calcium and Vitamin D Participants will be in energy balance and consume 1.7 g protein/kg BW/day. Energy Balance Maltodextrin Participants will be in energy balance and consume 1.7 g protein/kg BW/day. Caloric Restriction and High Protein Protein Participants will be calorie restricted to 30 kcal/kg FFM/day and consume 1.7 g protein/kg BW/day. Caloric Restriction and High Protein Maltodextrin Participants will be calorie restricted to 30 kcal/kg FFM/day and consume 1.7 g protein/kg BW/day. Caloric Restriction and Normal Protein Caloric Restriction Participants will be calorie restricted to 30 kcal/kg FFM/day and consume 0.8 g protein/kg BW/day.
- Primary Outcome Measures
Name Time Method Change in Circulating IGF-1 Baseline and day 6 Change in Resting Metabolic Rate Baseline and day 6 Change in Marker of Bone Formation (P1NP) Baseline and day 6 Change in Marker of Bone Resorption (CTx) Baseline and day 6
- Secondary Outcome Measures
Name Time Method Change in Body Weight Baseline and day 6 Change in Perceived Hunger Baseline and day 6 Perceived hunger will be assessed using 0-100 visual analog scales. In this case, 100 means maximum hunger while 0 means minimal hunger.
Change in Body Fat Percentage Baseline and day 6 Change in Aerobic Fitness (VO2peak) Baseline and day 6 Analyzed in L/min rather than mL/kg/min to remove influence of weight loss.
Trial Locations
- Locations (1)
Sports and Exercise Nutrition Laboratory, Department of Nutrition and Health Sciences, Ruth Leverton Hall
🇺🇸Lincoln, Nebraska, United States