Skip to main content
OpenTrials
Completed

NCT Number: NCT01895179

Comparison of Time-Restricted Feeding Versus Grazing

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.

Completed

Looking for future studies?

Notify Me

Key information

Conditions

PreDiabetes Behavior Cardiovascular Diseases Diabetes Mellitus Endocrine System Diseases Fasting Feeding Behavior Glucose Metabolism Disorders Hyperinsulinism Insulin Resistance Intermittent Fasting Metabolic Diseases Nutritional and Metabolic Diseases Prediabetic State Vascular Diseases

Age range

35 year–70 year

Sex eligibility

Male

Study type

Interventional

Phase

Not applicable

Primary location

Pennington Biomedical Research Center

Baton Rouge, Louisiana, 70808, United States

About this study

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.

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

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

Treatment and study plan

Time-Restricted Feeding

Other

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.

Grazing

Other

Grazing involves eating meals spread out over the course of the day.

Primary outcomes

  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 outcomes

  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).

Sponsors and collaborators

Lead sponsor

Pennington Biomedical Research Center

Other

Registry information

Official study title

Time-Restricted Feeding to Improve Glucose Tolerance and Vascular Condition

Acronym: TIMED EATING

Important dates

Study start
2013
Primary completion
2017
Study completion
2017
First posted
Jul 10, 2013
Registry last updated
Mar 16, 2018

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

Related clinical trials

Published trials that share one or more normalized conditions with this study.