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Influence of Flavonoids and Caffeine Supplementation on Resting Metabolism

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. Identifier: NCT03752125
Recruitment Status : Completed
First Posted : November 22, 2018
Last Update Posted : July 4, 2019
University of North Carolina, Chapel Hill
Information provided by (Responsible Party):
Appalachian State University

Brief Summary:
The purpose of this study is to compare the effect of ingesting caffeine and mixed flavonoids (4 capsules, split between breakfast and lunch) on energy expenditure and fat oxidation in a metabolic chamber with 20 women (non-obese, healthy, ages 20-47 years, pre-menopausal). We hypothesize that based on the existing literature, ingestion of a double dose of the caffeine-mixed flavonoid supplement compared to placebo will increase fat oxidation and increase 24 h energy expenditure by about 75 kilocalories.

Condition or disease Intervention/treatment Phase
Diet Modification Dietary Supplement: Flavonoid, caffeine Dietary Supplement: Placebo Not Applicable

  Show Detailed Description

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Study Type : Interventional  (Clinical Trial)
Actual Enrollment : 25 participants
Allocation: Randomized
Intervention Model: Crossover Assignment
Intervention Model Description: Randomized, crossover
Masking: Double (Participant, Investigator)
Masking Description: Flavonoid and placebo capsules
Primary Purpose: Treatment
Official Title: A Randomized, Cross-Over Clinical Trial to Evaluate the Acute Effects of Mixed Flavonoid and Caffeine Ingestion on Energy Expenditure and Fat Oxidation in Healthy Adult Women
Actual Study Start Date : April 22, 2018
Actual Primary Completion Date : December 15, 2018
Actual Study Completion Date : April 19, 2019

Resource links provided by the National Library of Medicine

MedlinePlus related topics: Caffeine

Arm Intervention/treatment
Experimental: Flavonoid, caffeine
Flavonoid, caffeine capsules
Dietary Supplement: Flavonoid, caffeine
2 flavonoid/caffeine capsules before breakfast, 2 capsules before lunch

Placebo Comparator: Placebo
Placebo capsules
Dietary Supplement: Placebo
2 placebo capsules before breakfast, 2 capsules before lunch

Primary Outcome Measures :
  1. 24-hour energy expenditure (kilocalories/minute) from continuous respiratory exchange measurements (oxygen consumption, carbon dioxide production) in a metabolic chamber [ Time Frame: 24 hours ]
    Energy expenditure (kilocalories) over 24 h in metabolic chamber with oxygen consumption and carbon dioxide production analyzers whereby energy expenditure is calculated from respiratory exchange data (oxygen consumption, carbon dioxide production) using standard equations

Secondary Outcome Measures :
  1. 24-hour fat oxidation (fat grams oxidized per minute) from continuous respiratory exchange measurements (oxygen consumption, carbon dioxide production) in a metabolic chamber [ Time Frame: 24 hours ]
    Fat oxidation (fat grams) over 24 h in metabolic chamber with oxygen consumption and carboh dioxide production analyzers whereby fat oxidation (grams/minute) is calculated from respiratory exchange data (oxygen consumption, carbon dioxide production) using standard equations

Information from the National Library of Medicine

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Ages Eligible for Study:   20 Years to 47 Years   (Adult)
Sexes Eligible for Study:   Female
Gender Based Eligibility:   Yes
Accepts Healthy Volunteers:   Yes

Inclusion Criteria:

  • Women, ages 20 to 47 years
  • Body mass index (BMI) between 18.5 and 33 kg/m2 (normal weight, overweight, mild obesity)
  • Weight during the past 6 months has been somewhat stable (+/- 12 lbs)
  • Low-to-moderate caffeine intake, defined as consuming on average: less than 3 servings per day of coffee (each about 8 fl. oz.) and/or energy drinks with caffeine; less than 3 soft drinks with caffeine and tea per day
  • Premenopausal (self-report)
  • Willingness to maintain habitual diet and physical activity patterns, and not lose weight throughout the study period
  • Understands and agrees to all study procedures and signs the form providing informed consent to participate in the study
  • Willingness to report and maintain normal schedule of hormonal therapy including oral contraceptive pills, hormonal IUD, Nuva Ring, or DepoProvera injections.
  • Normal thyroid function as determined from a blood sample collected during pre-study baseline testing.
  • Not pregnant as determined by a urine pregnancy test during pre-study baseline testing and prior to the second chamber session, and not planning to become pregnant during the study.
  • Willingness to avoid vigorous exercise the day before each metabolic chamber session (e.g., intense running, cycling, swimming for 30 minutes and longer).

Exclusion Criteria:

  • Taking medications for or suffering from a medical condition that may impact results related to metabolism (e.g. thyroid disorders, diabetes, mental disorders such as anxiety or depression, heart disease, arthritis, cancer).
  • Heavy exerciser (defined as more than 300 minutes per week of moderate to vigorous exercise within the last two weeks)
  • Thyroid hormone levels outside of the normal laboratory reference range
  • Pregnant or lactating, or planning to become pregnant during the study
  • Recent use of antibiotics (within last two weeks)
  • History of smoking during the six months prior to study
  • Recent signs or symptoms of infection, including cold or flu-like symptoms (within last 2 weeks)
  • Conditions or diseases the investigator believes would interfere with ability to provide consent, comply with the study protocol, which might confound the interpretation of the study results or put the person at undue risk. These include the disease list above and other health problems that would make it difficult to comply with two 24-hour periods of confinement in the metabolic chamber such as panic disorder, cardiac arrhythmias, musculoskeletal disorders such as low back pain and osteoarthritis, and gastrointestinal disorders including reactions to supplements with caffeine and vitamin C, and food allergies.
  • Inability or unwillingness to consume the foods that will be included in the provided meals when staying in the chamber
  • History of drug or alcohol abuse (>5 standard drinks per day)
  • Taking herbal supplements or medications that may influence metabolism within 14 days prior to the study, including supplements containing bitter orange, guarana, fucoxanthin, and green coffee bean, and medications such as Meridia, Xenical, LipoRidAM, Advantra-Z, NuPhedrine, and Slim-10.
  • Current consumption (or unwilling to stop intake 2 weeks prior) of flavonoid supplements, or a heavy consumer of green tea (>3 cups per day)
  • Near-daily use of tablets containing caffeine (e.g., NoDoz) (or unwillingness to stop 2 weeks prior to the study).
  • High intake of caffeine from coffee, tea, energy drinks with caffeine, and soft drinks containing caffeine (or unwillingness to reduce intake for 2 weeks prior to the study and during the 4-week study).
  • Prone to panic attacks when confined in a small room, especially when consuming caffeine.

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 identifier (NCT number): NCT03752125

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United States, North Carolina
Appalachian State University Human Performance Lab, North Carolina Research Campus
Kannapolis, North Carolina, United States, 28081
Sponsors and Collaborators
Appalachian State University
University of North Carolina, Chapel Hill
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Principal Investigator: David C Nieman, DrPH Appalachian State Univ

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Responsible Party: Appalachian State University Identifier: NCT03752125     History of Changes
Other Study ID Numbers: 18-0257
First Posted: November 22, 2018    Key Record Dates
Last Update Posted: July 4, 2019
Last Verified: July 2019
Individual Participant Data (IPD) Sharing Statement:
Plan to Share IPD: No

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Studies a U.S. FDA-regulated Drug Product: No
Studies a U.S. FDA-regulated Device Product: No

Keywords provided by Appalachian State University:
energy expenditure
fat metabolism

Additional relevant MeSH terms:
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Central Nervous System Stimulants
Physiological Effects of Drugs
Phosphodiesterase Inhibitors
Enzyme Inhibitors
Molecular Mechanisms of Pharmacological Action
Purinergic P1 Receptor Antagonists
Purinergic Antagonists
Purinergic Agents
Neurotransmitter Agents