Time-Restricted Eating and Muscle Hypertrophy

Sponsor

California State University, Fullerton (Other)

Overall Status

Suspended

CT.gov ID

NCT04000750

Collaborator

San Francisco State University (Other)

Enrollment

Location

Arms

29.3

Anticipated Duration (Months)

1.4

Patients Per Site Per Month

Study Details

Study Description

Brief Summary

The purpose is to examine the effects of time-restricted eating (TRE; consuming all calories within an 8-hour period each day) vs. normal eating (CON; consuming same kcals and protein as TRE, but during a 10-13 hr eating window each day) during 8 weeks of resistance exercise on body composition and muscle mass (whole muscle and single fiber), muscular performance, anabolic protein signaling, single muscle fiber characteristics, and the gut microbiome in well-trained young men and women.

Condition or Disease	Intervention/Treatment	Phase
Muscle Hypertrophy Healthy and Well-Trained Men and Women	Other: Time Restricted Eating Other: Normal Feeding Other: Resistance Training Dietary Supplement: Whey Protein	N/A

Detailed Description

The primary goal pertains to muscle hypertrophy (not fat loss), thus all participants will be placed in a 10% caloric surplus.

Study Design

Study Type:

Interventional

Anticipated Enrollment :

40 participants

Allocation:

Randomized

Intervention Model:

Parallel Assignment

Masking:

Double (Investigator, Outcomes Assessor)

Masking Description:

Participants will know their group. Training and Nutrition research team members will know the participants group. Data analysis team will be blinded to condition.

Primary Purpose:

Other

Official Title:

The Influence of 16:8 Time-Restricted Eating on Resistance Exercise-Induced Skeletal Muscle Hypertrophy

Actual Study Start Date :

Jun 24, 2019

Anticipated Primary Completion Date :

Jul 1, 2021

Anticipated Study Completion Date :

Dec 1, 2021

Arms and Interventions

Arm	Intervention/Treatment
Experimental: Time Restricted Eating (16:8) Participants will consume all calories within an 8 hour window each day.	Other: Time Restricted Eating Diet will be tracked and reported every day to a qualified dietitian. Other: Resistance Training 8 weeks of supervised and programmed whole body resistance training, performed 4x per week Dietary Supplement: Whey Protein Consumed on all exercise days.
Active Comparator: Control Participants will consume all calories within a ~12 hour window each day (4 separate meals + needed snacks).	Other: Normal Feeding Diet will be tracked and reported every day to a qualified dietitian. Other: Resistance Training 8 weeks of supervised and programmed whole body resistance training, performed 4x per week Dietary Supplement: Whey Protein Consumed on all exercise days.

Arm

Intervention/Treatment

Experimental: Time Restricted Eating (16:8)

Participants will consume all calories within an 8 hour window each day.

Other: Time Restricted Eating

Diet will be tracked and reported every day to a qualified dietitian.

Other: Resistance Training

8 weeks of supervised and programmed whole body resistance training, performed 4x per week

Dietary Supplement: Whey Protein

Consumed on all exercise days.

Active Comparator: Control

Participants will consume all calories within a ~12 hour window each day (4 separate meals + needed snacks).

Other: Normal Feeding

Diet will be tracked and reported every day to a qualified dietitian.

Other: Resistance Training

8 weeks of supervised and programmed whole body resistance training, performed 4x per week

Dietary Supplement: Whey Protein

Consumed on all exercise days.

Outcome Measures

Primary Outcome Measures

Changes in Muscle Size - Lower Body [Pre, Mid (4 weeks), and Post (8 weeks)]
via Ultrasound
Changes in Muscle Size - Upper Body [Pre, Mid (4 weeks), and Post (8 weeks)]
via Ultrasound
Changes in Fiber Type-Specific Size [Pre and Post (week 8)]
Single muscle fiber analysis
Changes in Body composition [Pre, Mid (4 weeks), and Post (8 weeks)]
via BodPod
Acute Exercise Induced Fiber Type-Specific Anabolic Signaling (Total Concentration and Phosphorylation Status) [Day 1 of exercise training]
Men only; assessed via single fiber Simple Western

Secondary Outcome Measures

Changes in Maximal Strength [Pre and Post (week 8)]
1RM on bench press, squat, and leg extension
Changes in Maximal Muscular Endurance [Pre and Post (week 8)]
Maximal repetitions on bench press and leg press
Changes in Gut Microbiome [Pre, Mid (week 2, 4, 6), and Post (week 8)]
via stool sample
Changes in Fiber Type Composition [Pre and Post (week 8)]
Single Fiber via SDS-PAGE
Changes in Fiber Type-Specific Resting Anabolic Signaling (Total Concentration and Phosphorylation Status) [Pre and Post (week 8)]
via single fiber Simple Western
Changes in Mood [Weekly for duration of the intervention (8 weeks)]
via Questionnaire
Changes in Enjoyment of Diet [Weekly for duration of the intervention (8 weeks)]
via Questionnaire
Changes in Sleep (total and quality) [Weekly for duration of the intervention (8 weeks)]
via Questionnaire
Changes in Menstrual Cycle [Pre, Mid (week 4), and post (week 8)]
via Questionnaire; women only
Total Training Volume [After 8 weeks]
Nutrient Intake [Daily, starting 7 days before the study and continuing for 8 additional weeks]
Total Kcal and grams of protein, fat, and carbohydrates

Eligibility Criteria

Criteria

Ages Eligible for Study:

18 Years to 35 Years

Sexes Eligible for Study:

All

Accepts Healthy Volunteers:

Yes

Inclusion Criteria:

18-35 years old with <25% (men) or <30% (women) body fat
have experience in resistance exercise for the whole body and performed resistance exercise at least 3 times per week the last 12 months
be able to perform all necessary exercises with safe technique and no pain
be able to squat 1.5x (men) or 1x (women) body weight
be able to bench press 1.1x (men) or 0.55x (women) body weight
be on a non-specialized, mixed macronutrient diet
have a lifestyle which enables a reasonably consistent 7+ hours of sleep per night
be free of any current joint, musculoskeletal, and/or neuromuscular injuries

Exclusion Criteria:

have any known current illness, prohibitive muscular or neuromuscular problem, hypertension, cardiac, pulmonary, liver, kidney, insulin or any other metabolic disorders (e.g. Type I or Type II diabetes)
are lactose intolerant or unable to consume whey protein for any reason
are on any medications known to affect protein metabolism
have taken antibiotics in the last 6 months
cannot refrain from consuming any alcoholic beverages, nicotine, or marijuana (or derivative) for a period of 48 hours prior to data collection (pre and post testing)
consume alcohol >2x per week
consume any analgesic or anti-inflammatory drug(s), prescription or non-prescription, chronically or within 48 hours of data collection
consume any recreational drug(s), prescription or non-prescription, legal or illegal, chronically or within 30 days of data collection
consume any caffeine or food within 12 hours of data collection
cannot refrain from physical exercise (outside of activities of daily living) outside of what is prescribed by the research team for the duration of the study
cannot refrain from using recovery methods such as electric stimulation, hot/cold therapy, massage, chiropractic, or personal air/water devices (Normatech, etc.)
have utilized any anabolic steroid, currently or in the past
cannot refrain from consumption of any supplementation (creatine, multivitamin, fish oil, protein powder, BCAA, pre-workouts, etc.) outside of what is provided
cannot refrain from consuming any supplemental pro or prebiotics or other items that intentionally alter the gut microbiome
fail to adhere to the nutritional guidelines or miss >3 of the exercise sessions
were recently pregnant, trying to become pregnant, or are currently breastfeeding