Effects of Low Fat Versus Low Carbohydrate Diets on Energy Metabolism

Effect of Low Fat Versus Low Carbohydrate Diets on Energy Metabolism

Background:

Researchers want to learn how different diets affect hormone levels, body weight, energy expenditure, liver fat, and more. To do this, they will use specialized techniques and food plans. This is not a weight loss study.

Objective:

To better understand how low-fat and low-carbohydrate foods affect health.

Eligibility:

Men and women ages 18-50 who have a stable body weight and can exercise daily

Design:

Participants will have a screening visit that lasts 4-6 hours. It will include:

Medical history

Physical exam

Fasting blood and urine tests

Questionnaires

Trying foods from the study

Participants will be admitted to the Clinical Center and will stay for 4 weeks without leaving. They can have visitors.

Participants will wear activity and glucose monitors throughout the study. They will be weighed daily and will complete daily exercise. They will eat 3 meals daily, plus snacks. They will give urine, saliva, and blood samples. They will fill out questionnaires and rate their hunger, appetite, and sense of taste. They will have body scans. For the scans, they will lie in a machine that takes X-ray pictures of the body.

Participants will complete activities to measure how many calories they burn and how the diets affect them:

Participants will drink special liquids to measure calories burned, sugar, and sense of taste.

Participants will wear a plastic hood while resting.

Participants will stay alone in a special room for 24 hours.

Participants will eat a low-carb, high-fat diet for 2 weeks and a high-carb, low-fat diet for 2 weeks.

Participants may be dismissed if they purposefully use the study to try to change their body weight.

Sponsoring Institution: National Institute of Diabetes and Digestive and Kidney Diseases

...

Study Overview

Detailed Description

Competing theories about obesity and its treatment contrast the relative roles of dietary fat versus carbohydrate on promotion of excessive calorie intake. Advocates of low-carbohydrate diets propose that diets high in carbohydrates lead to elevated insulin secretion and increased calorie intake. Alternatively, proponents of low-fat diets argue that diets high in fat promote passive overconsumption due to the high energy density and low satiety index of high-fat foods. Therefore, we will conduct a feeding study in 20 adult men and women to investigate the differences in ad libitum energy intake resulting from consuming two test diets for a pair of 2-week periods in a randomized, crossover design during a single 4-week inpatient period. The test diets presented to participants will be matched for calories and protein, but the low-carbohydrate diet (approximately10% of calories) will be high in fat (approximately75% of calories) whereas the low-fat diet will be high in carbohydrates (approximately75% of calories) and low in fat (approximately 10% of calories).

Study Type

Interventional

Enrollment (Actual)

21

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

    • Maryland
      • Bethesda, Maryland, United States, 20892
        • National Institutes of Health Clinical 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

Ages Eligible for Study

18 years to 50 years (Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

All

Description

  • INCLUSION CRITERIA:

    1. Adults age 18-50 years, male and female
    2. Weight stable (less than or equal to 5 % over past 6 months) as determined by volunteer report
    3. Body mass index (BMI) greater that or equal to 20kg/m2
    4. Body weight greater than or equal to 53 kg
    5. Able to complete daily bouts of stationary cycling at a moderate rate and intensity with a heart rate (HR) equal to or greater than 0.3(SqrRoot) (220-age-HRrest)+HRrest but not exceeding 0.4(SqrRoot) (220-age-HRrest)+HRrest and no signs of arrhythmia

EXCLUSION CRITERIA:

  1. Evidence of metabolic or cardiovascular disease, or disease that may influence metabolism (e.g. cancer, diabetes, thyroid disease)
  2. Taking any prescription medication or other drug that may influence metabolism (e.g. diet/weight-loss medication, asthma medication, blood pressure medication, psychiatric medications, corticosteroids, or other medications at the discretion of the PI and/or study team)
  3. Positive pregnancy test or lactation as determined by volunteer report (women only)
  4. Participating in a regular exercise program (> 2h/week of vigorous activity) as determined by volunteer report
  5. Hematocrit <37% (women only)
  6. Hematocrit < 40% (men only)
  7. Caffeine consumption > 300 mg/day as determined by volunteer report
  8. Regular use of alcohol (> 2 drinks per day), tobacco (smoking or chewing) amphetamines, cocaine, heroin, or marijuana over past 6 months as determined by volunteer report
  9. Psychological conditions such as (but not limited to) eating disorders, claustrophobia, clinical depression, bipolar disorders, that would be incompatible with safe and successful participation in this study, as determined by investigators.

    1. Past or present history of eating disorders as determined by volunteer report
    2. Past or present history of claustrophobia since part of the protocol will involve being confined to a small room for whole-body indirect calorimetry and being in an MRI scanner for liver fat measures
  10. Implants, devices, or foreign objects implanted in the body that interfere with the Magnetic Resonance procedures
  11. Volunteers with strict dietary concerns (e.g. vegetarian or kosher diet, food allergies)
  12. Volunteers unwilling or unable to give informed consent
  13. Non-English speakers due to unavailability of required questionnaires in other languages

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
Intervention / Treatment
Active Comparator: LCHF diet then LFHC diet
Low carbohydrate, high fat (LCHF) diet then low fat, high carbohydrate diet (LFHC) diet
low-carbohydrate, high-fat (LCHF)diet
low-fat, high-carbohydrate (LFHC) diet
Active Comparator: LFHC diet then LCHF diet
Low fat, high carbohydrate diet (LFHC) diet then low carbohydrate, high fat (LCHF) diet
low-carbohydrate, high-fat (LCHF)diet
low-fat, high-carbohydrate (LFHC) diet

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Ad Libitum Energy Intake
Time Frame: 14 days
Ad libitum energy intake averaged over 14 days for each diet, measured in kilocalories (kcal) per day.
14 days

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Mean Glucose During Oral Glucose Tolerance Test (OGTT)
Time Frame: Day 14
An OGTT was performed at the end of each 14 day period and the mean glucose was calculated
Day 14
Change in Body Weight
Time Frame: Baseline and day 14
Change in body weight from baseline to day 14 for each diet, measured in kilograms (kg)
Baseline and day 14
Change in Body Fat Mass
Time Frame: Baseline and day 14
Change in body fat mass from baseline to day 14 for each diet, measured in kilograms (kg). Body fat mass was measured using Dual-energy X-ray absorptiometry (DXA) measurements.
Baseline and day 14
Change in Cholesterol
Time Frame: Baseline and day 14
Change in cholesterol from baseline to day 14 for each diet
Baseline and day 14
Change in Triglycerides
Time Frame: Baseline and day 14
Change in triglycerides from baseline to day 14 for each diet
Baseline and day 14
Change in TSH
Time Frame: Baseline and day 14
Change in thyroid stimulating hormone (TSH) from baseline to day 14 for each diet
Baseline and day 14
Change in C-peptide
Time Frame: Baseline and day 14
Change in C-peptide from baseline to day 14 for each diet
Baseline and day 14
Change in CRP
Time Frame: Baseline and day 14
Change in C-reactive protein (CRP) from baseline to day 14 for each diet
Baseline and day 14

Collaborators and Investigators

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

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.

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)

April 15, 2019

Primary Completion (Actual)

March 4, 2020

Study Completion (Actual)

September 1, 2020

Study Registration Dates

First Submitted

March 15, 2019

First Submitted That Met QC Criteria

March 15, 2019

First Posted (Actual)

March 18, 2019

Study Record Updates

Last Update Posted (Actual)

June 3, 2021

Last Update Submitted That Met QC Criteria

May 11, 2021

Last Verified

December 4, 2020

More Information

Terms related to this study

Other Study ID Numbers

  • 190067
  • 19-DK-0067 (Other Identifier: NIH Clinical Center)

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.

Clinical Trials on Healthy

Clinical Trials on LCHF diet

3
Subscribe