Effects of Protein Timing and Resistance Exercise on Fat Metabolism

Healthy Clinical Trial

Official title:

The Effect of Protein Timing and Resistance Exercise on Lipolysis and Fat Oxidation in Resistance-Trained Women

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT03573687
• Other study ID #: NPRO
• Status: Completed
• Phase: N/A
• Start date: March 20, 2017
• Est. completion date: February 28, 2018

Study information

• Verified date: July 2018
• Source: Florida State University
• Contact: n/a
• Is FDA regulated: No
• Study type: Interventional

Clinical Trial Summary

The extent to which resistance exercise training and protein timing effects localized (belly fat) and systemic (whole body) fat metabolism in resistance-trained women is unknown. Therefore, this study will assess subcutaneous abdominal adipose tissue lipolytic rate and whole body substrate utilization over the course of two trials: 1) consuming casein protein during the day, and 2) consuming casein protein at night, before bed.

Description:

Nighttime eating, and specifically eating after dinner, has attracted significant attention in recent years, particularly for the onslaught of media claiming the negative implications on body weight and overall health. Some studies have indeed indicated that chronically eating high-energy, mixed-meals rich in carbohydrates (CHO) and fats at night contributes to weight gain and abdominal obesity. However, research to support these negative claims is scant. Conversely, the practice of nighttime eating of small protein (PRO) snacks has been widely utilized anecdotally in populations such as bodybuilders in an attempt to avoid catabolism of muscle mass during the sleeping hours.

It has been shown that nighttime consumption of small portions (<200 kcals) of PRO elicits beneficial effects on metabolism such as increased next-morning resting metabolic rate (RMR). Likewise, the combination of nighttime PRO consumption and RT improves factors that contribute to fat loss such as elevated muscle mass due to an increase in muscle protein synthesis and energy expenditure. Further, there is emerging research suggesting the benefits of nighttime PRO consumption on fat metabolism (specifically the subcutaneous abdominal adipose tissue [SCAAT]). The SCAAT is of particular interest in metabolism research, as the upper body subcutaneous tissue (i.e. SCAAT) supplies most of the circulating free fatty acids (FFA) during the overnight hours in lean individuals. Therefore, if one can optimize the timing of dietary PRO during a window at which SCAAT is elevated (nighttime), theoretically, mobilization and oxidation of fats could be optimized.

Research regarding nighttime eating, specifically regarding fat metabolism, is in its infancy, and thus, many gaps in the literature require elucidation. First, and certainly most importantly, the limited research studies examining the effects of nighttime PRO consumption have not methodologically matched for timing of PRO intake. Therefore, it is unclear whether any reported benefits of the published nighttime PRO studies were a consequence of the addition of PRO calories or specifically due to the consumption of PRO at night. Thus, in order to make optimal comparisons and conclusions, it is imperative to study the metabolic effects of dietary PRO consumed at night versus other times of day.

Therefore, the purpose of this project is to: 1) determine the effects of RT on post-exercise lipolytic rate in resistance-trained women; and 2) determine the effects of timing of acute protein PRO ingestion (nighttime PRO consumption [NP] and daytime PRO consumption [DP] trials) after a RT bout on SCAAT lipolytic rate, metabolic rate, and serum hormones (glucose, insulin, growth hormone, adiponectin, glycerol) throughout the day, overnight and into the next morning.

Recruitment information / eligibility

• Status: Completed
• Enrollment: 13
• Est. completion date: February 28, 2018
• Est. primary completion date: February 28, 2018
• Accepts healthy volunteers: Accepts Healthy Volunteers
• Gender: Female
• Age group: 18 Years to 35 Years

Eligibility

Inclusion Criteria:

• Healthy

• Resistance-trained (able to squat 1.0 times their body weight, and bench press 0.75 times body weight, adapted from ACSM Guidelines and piloted in our laboratory)

• Normal weight (BMI = 18.5-25 kg/m2; body fat <33%)

• Normally menstruating (on or off oral contraceptives)

• Females.

Exclusion Criteria:

• Uncontrolled thyroid dysfunction (not on medication)

• Musculoskeletal disorders

• Currently smoke

• Have milk allergies

• Currently take medications or supplements known to affect substrate metabolism.

Related Conditions & MeSH terms

• Healthy

Intervention

Dietary Supplement:
• Micellar Casein Protein
The micellar casein protein supplement (PRO, total protein content: 30 g, 120 kcals; 30 g micellar protein) and non-caloric sensory-matched placebo (PLA, 0kcals) will be specifically formulated by Dymatize® Nutrition FrieslandCampina® and consumed in a randomized order. Participants will consume the daytime supplement 30 minutes after RT and the nighttime supplement about 30 minutes before bedtime. The supplements will be premixed, taste-matched (chocolate), and provided in opaque shaker bottles.

Other:
• Resistance Exercise Training
Resistance exercise training (RT) will target the full body and exercises will be performed using a barbell. Exercises will be performed in the following order: back squat, bench press, Romanian deadlift, bent-over row, shoulder press, and reverse lunges)

Locations

Country	Name	City	State
United States	Institute for Sports Sciences and Medicine, Florida State University	Tallahassee	Florida

Sponsors (1)

Lead Sponsor	Collaborator
Florida State University

Country where clinical trial is conducted

United States, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Lipolysis	Lipolysis is the way that fat cells mobilize the stored fat to enter into blood circulation. Lipolysis can be measured using a technique called microdialysis. In short, a semi-permeable probe is inserted into the subcutaneous abdominal adipose tissue (SCAAT, or belly fat). Saline combined with a minute amount of ethanol is perfused into the SCAAT, and interstitial fluid is collected out. The concentration of ethanol in the interstitial fluid sample is an indicator of blood flow within the tissue. Glycerol and free fatty acid concentration is measured to indicated rate of fat metabolism (specifically glycerol). The area under the curve for glycerol concentration over time (AUCgly) will be calculated for each of time point. Microdialysis dialysate samples will be measured during the NP and DP trials at fifteen separate time points throughout each visit.	18 hours
Secondary	Hormone Concentrations	Serum samples will be analyzed for the assessment of glucose, insulin, and growth hormone on collections 1, 3, 4, and 5. Serum glycerol will be assessed at 5 time points. Serum catecholamines will be assessed at time points 1, 2 and 3. The timeline for blood collections is as follows: During microdialysis probe equilibration (~1600 hours); Half way through the RT protocol (~1800 hours, after the third exercise: Romanian deadlift); Thirty minutes after daytime supplement (1900 hours); Thirty minutes after nighttime supplement (2300 hours), and; The following morning after RMR (0750 hours)	18 hours
Secondary	Fat oxidation	Fat oxidation is when those stored fats enter into the muscle cells and are able to be oxidized to form energy. Fat oxidation will be quantified by measuring resting metabolic rate (RMR, amount of calories burned at rest) and respiratory exchange ratio (RER, measure of whole-body substrate utilization) using a dilution technique and open-circuit indirect calorimetry (ParvoMedics TrueOne 2400 metabolic cart, Sandy, UT). This technique uses a ventilated hood covering the participants' head and torso. Participants will be asked to remain awake, quiet, and as motionless as possible in a semi-recumbent position in a quiet, dark, climate-controlled isolated room (20-23°C). Resting metabolism will be measured on four separate occasions.	18 hours