Long-term Effects of Green Tea on Gut Flora, Fat Absorption, Body Composition and Resting Energy Expenditure

March 17, 2016 updated by: Maastricht University Medical Center
Green tea may have positive effects for weight control and on body composition via several approaches such as a positive effect on the gut flora, a decrease in fat absorption from the intestines and an increase in resting energy expenditure.

Study Overview

Status

Completed

Conditions

Intervention / Treatment

Detailed Description

Green tea may have positive effects for weight control and on body composition via several approaches such as a positive effect on the gut flora, a decrease in fat absorption from the intestines and an increase in resting energy expenditure. We would like to investigate the long-term effects of green tea on gut flora, fat absorption, resting energy expenditure and body composition.

The study will be conducted in a randomized, placebo-controlled, double-blind parallel design with four groups consisting of control groups and green tea groups with normal weight subjects and obese subjects. At three time points (baseline, 6 weeks and 12 weeks) faeces are collected for analyzing the gut flora composition and fat content. Furthermore, measurements of resting energy expenditure and body composition will be conducted. Activity will be measured during three weeks (baseline, week 6 and week 12).

a hundred healthy subjects (50 males and 50 females) with a BMI between 18.5-25 kg/m2 and ≥30 kg/m2 and aged between 18-50 years will be included in the study. All subjects will be non-smoking, non tea-drinkers, weight stable, dietary unrestraint, and at most moderate alcohol and caffeine consumers. Subjects will be free of medication except for oral contraceptives use in women.

Intervention (if applicable):

Subjects will receive either green tea or placebo in capsule form after their baseline measurement, which they have to consume three times daily for a period of twelve weeks.

Study Type

Interventional

Enrollment (Actual)

70

Phase

  • 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

  • Netherlands
      • Maastricht, Netherlands, 6229 ER
        • Maastricht University, Human Biology

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

Ages Eligible for Study

18 years to 50 years (Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

All

Description

Inclusion Criteria:

  • BMI between 18.5-25 kg/m2 and ≥30 kg/m2
  • Age between 18-50 years
  • Healthy
  • Weight stable
  • Dietary unrestraint
  • Not using a more than moderate amount of alcohol (>10 consumptions/wk)
  • Not using more than 100 mg caffeine per day
  • Not drinking tea
  • Not using probiotics
  • Being weight stable (weight change < 3kg during the last 6 months)
  • Dietary unrestraint
  • Not using antibiotics during the last 6 months.
  • Free of medication except for oral contraceptives use in women.

Exclusion Criteria:

  • Not healthy
  • Smoking
  • Using a more than moderate amount of alcohol
  • Using more than 100 mg caffeine per day
  • Drinking tea
  • Using probiotics
  • Not being weight stable
  • Dietary restraint
  • Using medication or supplements except for oral contraceptives in women
  • Using antibiotics
  • Not meeting the criteria for BMI and age.
  • Pregnant or lactating women
  • Having allergies for the used food items will also be excluded from participation.

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: Parallel Assignment
  • Masking: Double

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Green tea, normal weight
Subjects with a BMI 18.5-25 kg/m2 will receive green tea capsules, which they have to consume daily for a period of twelve weeks
Dietary supplement: green tea (757 mg/capsule [84.5 mg EGCG + 2.1 mg caffeine ]
Subjects will receive green tea (757 mg/capsule [84.5 mg EGCG + 2.1 mg caffeine ], 3 capsules with each breakfast, lunch and dinner)in capsule form after their baseline measurement, which they have to consume daily for a period of twelve weeks.
Placebo Comparator: Placebo, normal weight
Subjects with a BMI 18.5-25 kg/m2 will receive placebo capsules, which they have to consume daily for a period of twelve weeks
Dietary supplement: placebo
Subjects will receive placebo (soy oil; 757 mg/capsule, 3 capsules with each breakfast, lunch and dinner) in capsule form after their baseline measurement, which they have to consume daily for a period of twelve weeks.
Experimental: Green tea, overweight
Subjects with a BMI >30 kg/m2 will receive green tea capsules, which they have to consume daily for a period of twelve weeks
Dietary supplement: green tea (757 mg/capsule [84.5 mg EGCG + 2.1 mg caffeine ]
Subjects will receive green tea (757 mg/capsule [84.5 mg EGCG + 2.1 mg caffeine ], 3 capsules with each breakfast, lunch and dinner)in capsule form after their baseline measurement, which they have to consume daily for a period of twelve weeks.
Placebo Comparator: Placebo capsules, obese
Subjects with a BMI >30 kg/m2 will receive placebo capsules, which they have to consume daily for a period of twelve weeks
Dietary supplement: placebo
Subjects will receive placebo (soy oil; 757 mg/capsule, 3 capsules with each breakfast, lunch and dinner) in capsule form after their baseline measurement, which they have to consume daily for a period of twelve weeks.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Faeces are collected for analyzing the gut flora and fat absorption
Time Frame: At three time points (baseline, 6 weeks and 12 weeks)
The primary endpoint of this study is the change in gut flora; ratio firmicutes/bacteroidetes, changes in total faecal fat and change in body weight.
At three time points (baseline, 6 weeks and 12 weeks)

Secondary Outcome Measures

Outcome Measure
Time Frame
Resting energy expenditure (REE)
Time Frame: At three time points (baseline, 6 weeks and 12 weeks)
At three time points (baseline, 6 weeks and 12 weeks)
Respiratory quotient (RQ)
Time Frame: At three time points (baseline, 6 weeks and 12 weeks)
At three time points (baseline, 6 weeks and 12 weeks)
Three frequency eating questionnaire (TFEQ)
Time Frame: At three time points (baseline, 6 weeks and 12 weeks)
At three time points (baseline, 6 weeks and 12 weeks)
Body composition: BMI, body fat percentage, fat mass index (FMI)
Time Frame: At three time points (baseline, 6 weeks and 12 weeks)
At three time points (baseline, 6 weeks and 12 weeks)
Body fat distribution: waist circumference, waist-to-hip ratio (WHR
Time Frame: At three time points (baseline, 6 weeks and 12 weeks)
At three time points (baseline, 6 weeks and 12 weeks)

Collaborators and Investigators

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

Sponsor

Maastricht University Medical Center

Investigators

  • Principal Investigator: Margriet Westerterp-Plantenga, Prof. Dr., Maastricht University, Department of Human Biology

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

June 1, 2012

Primary Completion (Actual)

December 1, 2014

Study Completion (Actual)

April 1, 2015

Study Registration Dates

First Submitted

March 7, 2012

First Submitted That Met QC Criteria

March 15, 2012

First Posted (Estimate)

March 16, 2012

Study Record Updates

Last Update Posted (Estimate)

March 18, 2016

Last Update Submitted That Met QC Criteria

March 17, 2016

Last Verified

May 1, 2013

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • NL38773

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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