Time Restricted Feeding in Male Runners

March 30, 2020 updated by: USDA, Western Human Nutrition Research Center

The Effects of Four Weeks of Intermittent Fasting on Resting Energy Expenditure, Satiety Hormones, Body Composition, and Performance in Competitive Runners

This is a cross-over intervention study designed to evaluate how four weeks of time restricted feeding (16 hours fasting and 8 hours feeding), compared to four weeks of a more traditional eating pattern (12 hours fasting and 12 hours feeding), affects resting energy expenditure, subjective and biochemical markers of satiety and hunger, body composition, cardiovascular health, substrate utilization and fitness in male competitive runners.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Completed

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Detailed Description

Weight loss and improvements in body composition (increasing muscle mass and decreasing fat mass) are common goals for both dieters and athletes. Although a traditional method of achieving this has been accomplished through caloric restriction, an alternate method that is becoming increasingly popular is fasting. Fasting is described as the absence of food and/or calorie-containing beverage consumption for a period of time. The majority of people fast for 8-10 hours daily, which occurs during the overnight period when people are asleep Intermittent fasting, specifically time-restricted feeding (TRF), has recently gained popularity because it is a more sustainable means of practicing fasting and it has been shown to enhance the loss of fat mass with or without caloric restriction. It has also been shown to enhance overall health due to reports of reduced fasting glucose, insulin resistance, triglycerides, and reduced total and low-density lipoprotein (LDL) cholesterol levels in obese women. Despite its growing popularity among athletes, there is scarce research on how adhering to this type of diet pattern affects athletic performance and other biochemical markers related to health. The participants in this study will be randomly assigned to either a traditional (12/12) or a time restrictive (16/8) eating pattern in a crossover design. Each pattern will last for four weeks with a minimum two week washout in between, and the participants will consume the same calorie and macronutrient amounts based on recommendations made by the American College of Sports Medicine (ACSM) for both eating patterns. The 12/12 pattern will require subjects to consume 5 meals (breakfast, lunch, dinner, and two snacks) per day within a 12 hour period suggested to be around 8am, 10am, 12pm, 3pm, and 7pm. The 16/8 pattern will require subjects to consume 3 meals in an 8-hour period suggested to be around 12pm, 3pm, and 7pm. Subjects may only consume water, unsweetened coffee, or unsweetened tea (no artificial sweeteners) during their periods of fasting. Subjects will perform all exercise in the morning before 8 am in the fasted state. Subjects will visit the Western Human Nutrition Research Center (WHNRC) for test days at baseline (study day 1), after four weeks of the first dietary intervention (study day 28), and at the start (study day 43) and end of the second dietary intervention (study day 70), for a total of 4 test days over the duration of 10 weeks.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Actual)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
21

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • United States
    • California
      • Davis, California, United States, 95616
        • UC Davis, Western Human Nutrition Research Center

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

20 years to 40 years (Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

Male

Description

Inclusion Criteria:

  • Competitive runners who have been actively training for 3 or more years
  • Weigh a minimum of 110 lbs
  • Training 4-6 times per week and run a minimum of 20 miles per week
  • Competed in a race within past 12 months at a distance of 5 - 26.1 km
  • Willing to repeat same monthly training protocol during two 4-week interventions
  • VO2max range of 40-70 ml/kg/min

Exclusion Criteria:

  • Smoker
  • Take medications that have cardiovascular or metabolic effects
  • Taking dietary supplements
  • Following a restrictive diet including restricting calories or carbohydrates
  • Evidence of an eating disorder
  • Major injuries in past 3 months
  • Chronic disease that affects bone health, metabolism or the cardiorespiratory system
  • Present with any contra-indication to exercise testing (cardiovascular abnormalities) as evaluated by study physician

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Basic Science
  • Allocation: Randomized
  • Interventional Model: Crossover Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Experimental: Experimental Group 1
Order of treatment, time restrictive feeding (16 hours fasting and 8 hours eating) followed by traditional eating pattern (12 hours fasted and 12 hours eating).
Behavioral: Time Restrictive Feeding
Volunteers will adhere to a form of time restrictive feeding, 16 hours fasting and 8 hours eating per day.
Other Names:
  • Intermittent Fasting
Behavioral: Traditional Eating Pattern
Volunteers will adhere to a more traditional eating pattern, 12 hours fasted and 12 hours eating per day.
Other Names:
  • Normal Diet
Experimental: Experimental Group 2
Order of treatment, traditional eating pattern (12 hours fasted and 12 hours eating) followed by time restrictive feeding (16 hours fasting and 8 hours eating).
Behavioral: Time Restrictive Feeding
Volunteers will adhere to a form of time restrictive feeding, 16 hours fasting and 8 hours eating per day.
Other Names:
  • Intermittent Fasting
Behavioral: Traditional Eating Pattern
Volunteers will adhere to a more traditional eating pattern, 12 hours fasted and 12 hours eating per day.
Other Names:
  • Normal Diet

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Change in resting energy expenditure
Time Frame: Study day 1, 28, 43 and 70
Resting energy expenditure will be measured using a metabolic cart
Study day 1, 28, 43 and 70

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Change in body composition
Time Frame: Study day 1, 28, 43 and 70
Body composition, including fat mass and lean body mass, will be measured by dual-energy x-ray absorptiometry (DEXA) and expressed in kilograms (kg).
Study day 1, 28, 43 and 70
Change in substrate utilization during exercise
Time Frame: Study day 1, 28, 43 and 70
Carbohydrate and fat utilized for energy will be measured using a metabolic cart
Study day 1, 28, 43 and 70
Change in cardiovascular fitness
Time Frame: Study day 1, 28, 43 and 70
Time to run a 10 kilometer time trial on a treadmill expressed in minutes
Study day 1, 28, 43 and 70
Change in perceived feelings of hunger and fullness
Time Frame: Study day 1, 28, 43 and 70
Perceived hunger and fullness will be measured using a visual analog scale. Responses will be a mark on an unsegmented line from 0 or "not at all" to 5 or "extremely."
Study day 1, 28, 43 and 70
Change in glucagon, a biomarker of hunger and satiety
Time Frame: Study day 1, 28, 43 and 70
Fasting plasma will be analyzed for glucagon (pmol/L) as measured by enzyme-linked immunoabsorbant assay
Study day 1, 28, 43 and 70
Change in leptin, a biomarker of hunger and satiety
Time Frame: Study day 1, 28, 43 and 70
Fasting plasma will be analyzed for leptin (pmol/L) as measured by enzyme-linked immunoabsorbant assay
Study day 1, 28, 43 and 70
Change in ghrelin, a biomarker of hunger and satiety
Time Frame: Study day 1, 28, 43 and 70
Fasting plasma will be analyzed for ghrelin (pmol/L) as measured by enzyme-linked immunoabsorbant assay
Study day 1, 28, 43 and 70
Change in insulin
Time Frame: Study day 1, 28, 43 and 70
Fasting plasma will be analyzed for insulin (pmol/L) as measured by enzyme-linked immunoabsorbant assay
Study day 1, 28, 43 and 70
Change in total cholesterol, a biomarker of cardiovascular health
Time Frame: Study day 1, 28, 43 and 70
Fasting serum will be analyzed for total cholesterol (mmol/L) by Piccolo analyzer
Study day 1, 28, 43 and 70
Change in HDL cholesterol, a biomarker of cardiovascular health
Time Frame: Study day 1, 28, 43 and 70
Fasting serum will be analyzed for HDL cholesterol (mmol/L) by Piccolo analyzer
Study day 1, 28, 43 and 70
Change in LDL cholesterol, a biomarker of cardiovascular health
Time Frame: Study day 1, 28, 43 and 70
Fasting serum will be analyzed for LDL cholesterol (mmol/L) by Piccolo analyzer
Study day 1, 28, 43 and 70
Change in very low-density lipoprotein (VLDL), a biomarker of cardiovascular health
Time Frame: Study day 1, 28, 43 and 70
Fasting serum will be analyzed for very low-density lipoprotein (VLDL) cholesterol (mmol/L) by Piccolo analyzer
Study day 1, 28, 43 and 70
Change in triglycerides, a biomarker of cardiovascular health
Time Frame: Study day 1, 28, 43 and 70
Fasting serum will be analyzed for triglycerides (mmol/L) by Piccolo analyzer
Study day 1, 28, 43 and 70
Change in alanine aminotransferase, a biomarker of cardiovascular health
Time Frame: Study day 1, 28, 43 and 70
Fasting serum will be analyzed for alanine aminotransferase (IU/L) by Piccolo analyzer
Study day 1, 28, 43 and 70
Change in aspartate aminotransferase, a biomarker of cardiovascular health
Time Frame: Study day 1, 28, 43 and 70
Fasting serum will be analyzed for aspartate aminotransferase (IU/L) by Piccolo analyzer
Study day 1, 28, 43 and 70
Change in glucose
Time Frame: Study day 1, 28, 43 and 70
Fasting serum will be analyzed for glucose (mmol/L) by Piccolo analyzer
Study day 1, 28, 43 and 70

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
USDA, Western Human Nutrition Research Center

Collaborators

Collaborators

An organization other than the sponsor that provides support for a clinical study. This support may include activities related to funding, design, implementation, data analysis, or reporting.
University of California, Davis

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Principal Investigator: Gretchen Casazza, PhD, University of California, Davis

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
July 15, 2018

Primary Completion (Actual)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
March 24, 2020

Study Completion (Actual)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
March 24, 2020

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
June 15, 2018

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
June 15, 2018

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
June 26, 2018

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
April 1, 2020

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
March 30, 2020

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
March 1, 2020

More Information

Terms related to this study

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • TRF 1223350

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

Undecided

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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