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Comparison of Time-Restricted Feeding Versus Grazing (TIMED EATING)

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ClinicalTrials.gov Identifier: NCT01895179
Recruitment Status : Completed
First Posted : July 10, 2013
Last Update Posted : March 16, 2018
Information provided by (Responsible Party):
Courtney Peterson, Pennington Biomedical Research Center

Brief Summary:

The purpose of this pilot study is to find out what eating meals in a short time period early in the day (time-restricted feeding) versus eating meals spread out during the day (grazing) does to the body's ability to control blood sugar and to the health of its blood vessels.

The investigators hypothesize that time-restricted feeding will be more effective at improving glucose tolerance and vascular condition (inflammation and micro- and macro-vascular function) than grazing.

Condition or disease Intervention/treatment Phase
Prediabetes Insulin Resistance Vascular Diseases Other: Time-Restricted Feeding Other: Grazing Not Applicable

Detailed Description:
Each participant will eat according to one of the two eating schedules (grazing or time-restricted feeding) for 5 weeks, have a 7-week washout period, and then eat according to the other eating schedule for 5 weeks. Measurements of glucose homeostasis and vascular condition will be performed before and after a participant follows each eating schedule.

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Study Type : Interventional  (Clinical Trial)
Actual Enrollment : 8 participants
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: None (Open Label)
Primary Purpose: Prevention
Official Title: Time-Restricted Feeding to Improve Glucose Tolerance and Vascular Condition
Study Start Date : July 2013
Actual Primary Completion Date : November 2017
Actual Study Completion Date : November 2017

Arm Intervention/treatment
Experimental: Time-Restricted Feeding (early in the day eating)
Participants will consume all meals early in the day and within a 6-hour window.
Other: Time-Restricted Feeding
Time-restricted feeding is a variant of intermittent fasting that involves eating all of one's calories within a few hours each day (typically 4-9 hours), followed by a daily fast of 15-20 hours.

Placebo Comparator: Grazing
Participants will eat meals spread out over the course of the day.
Other: Grazing
Grazing involves eating meals spread out over the course of the day.

Primary Outcome Measures :
  1. Change in Glucose Tolerance [ Time Frame: Before and after 5 weeks on each feeding schedule ]
    Glucose tolerance and indices of glucose homeostasis will be determined using an Oral Glucose Tolerance Test (OGTT).

Secondary Outcome Measures :
  1. Change in Vascular Function [ Time Frame: Before and after 5 weeks on each feeding schedule ]
    Macro- and micro-vascular function will be assessed by Radial Artery Applanation Tonometry and by Orthogonal Polarization Spectroscopy. The endpoints measured by these two tests include aortic blood pressure, arterial stiffness, capillary density, and red blood cell velocity.

  2. Change in Inflammation and Metabolic Markers [ Time Frame: Before and after 5 weeks on each feeding schedule ]
    Serum markers of inflammation, such as C-Reactive Protein (CRP) and inflammatory cytokines, and of metabolic processes will be measured (composite measure).

Information from the National Library of Medicine

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Ages Eligible for Study:   35 Years to 70 Years   (Adult, Older Adult)
Sexes Eligible for Study:   Male
Accepts Healthy Volunteers:   Yes

Inclusion Criteria:

  • Are male
  • Overweight: Have a body mass index between 25 and 50 kg/m^2 inclusive (a number calculated from height and weight)
  • Are 35-70 years of age
  • Have a hemoglobin A1C between 5.5 - 6.4% or prior medical indication of prediabetes
  • Have a blood sugar level between 140 and 199 mg/dL two hours after drinking a sugary solution (OGTT)
  • Have been eating dinner at least 8.5 hours after eating breakfast at least 90% of the time during the past year
  • Have not fasted (go for a day without any food) more than 12 days total during the past year
  • Be willing to eat most meals at Pennington Biomedical and/or under supervision
  • Not eat any food other than that served by Pennington Biomedical
  • Not drink any alcohol, juice, or other beverages that have calories other than what is served by Pennington Biomedical
  • Keep water and no-calorie drinks like tea or diet soda the same during both of the timed eating periods
  • Be willing to eat your meals according to the fixed schedules

Exclusion Criteria:

  • Have diabetes or are on anti-diabetes medication
  • Have evidence of cardiovascular disease
  • Suffer from significant cardiovascular, renal (kidney), cardiac (heart), liver, lung or nervous system disease
  • Evidence of significant gastrointestinal issues or surgery that impacts nutrient absorption
  • Regularly use medications such as steroids, beta blockers, and adrenergic-stimulating agents
  • Are on any regular medicine that has not had the same dose for 1 month or longer
  • Have a clinically significant abnormality as measured by a blood test
  • Regularly drink alcohol (more than 2 servings per day)
  • Have to do any kind of heavy physical activity
  • Currently perform overnight shift work more than one day a week
  • Are not able to eat only the food served to you by Pennington Biomedical, while in the study
  • Are not able to stop drinking alcohol or other drinks with calories (e.g., soda, juice) other than what is served to you by Pennington Biomedical, while in the study

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT01895179

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United States, Louisiana
Pennington Biomedical Research Center
Baton Rouge, Louisiana, United States, 70808
Sponsors and Collaborators
Pennington Biomedical Research Center
Publications automatically indexed to this study by ClinicalTrials.gov Identifier (NCT Number):
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Responsible Party: Courtney Peterson, Instructor, Pennington Biomedical Research Center
ClinicalTrials.gov Identifier: NCT01895179    
Other Study ID Numbers: PBRC 13017
First Posted: July 10, 2013    Key Record Dates
Last Update Posted: March 16, 2018
Last Verified: March 2018
Keywords provided by Courtney Peterson, Pennington Biomedical Research Center:
Time-restricted feeding
Intermittent fasting
Insulin resistance
Glucose tolerance
Insulin sensitivity
Circadian rhythms
Additional relevant MeSH terms:
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Vascular Diseases
Insulin Resistance
Prediabetic State
Glucose Intolerance
Glucose Metabolism Disorders
Metabolic Diseases
Cardiovascular Diseases
Diabetes Mellitus
Endocrine System Diseases