Effects of Low Fat Versus Low Carbohydrate Diets on Energy Metabolism

NCT ID: NCT03878108

Last Updated: 2021-06-03

Study Results

Results available

Outcome measurements, participant flow, baseline characteristics, and adverse events have been published for this study.

View full results

Basic Information

Get a concise snapshot of the trial, including recruitment status, study phase, enrollment targets, and key timeline milestones.

Recruitment Status

COMPLETED

Clinical Phase

NA

Total Enrollment

21 participants

Study Classification

INTERVENTIONAL

Study Start Date

2019-04-15

Study Completion Date

2020-09-01

Brief Summary

Review the sponsor-provided synopsis that highlights what the study is about and why it is being conducted.

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

...

Detailed Description

Dive into the extended narrative that explains the scientific background, objectives, and procedures in greater depth.

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).

Conditions

See the medical conditions and disease areas that this research is targeting or investigating.

Healthy Healthy Volunteers

Study Design

Understand how the trial is structured, including allocation methods, masking strategies, primary purpose, and other design elements.

Allocation Method

RANDOMIZED

Intervention Model

CROSSOVER

Primary Study Purpose

BASIC_SCIENCE

Blinding Strategy

NONE

Study Groups

Review each arm or cohort in the study, along with the interventions and objectives associated with them.

LCHF diet then LFHC diet

Low carbohydrate, high fat (LCHF) diet then low fat, high carbohydrate diet (LFHC) diet

Group Type ACTIVE_COMPARATOR

LCHF diet

Intervention Type DIETARY_SUPPLEMENT

low-carbohydrate, high-fat (LCHF)diet

LFHC diet

Intervention Type DIETARY_SUPPLEMENT

low-fat, high-carbohydrate (LFHC) diet

LFHC diet then LCHF diet

Low fat, high carbohydrate diet (LFHC) diet then low carbohydrate, high fat (LCHF) diet

Group Type ACTIVE_COMPARATOR

LCHF diet

Intervention Type DIETARY_SUPPLEMENT

low-carbohydrate, high-fat (LCHF)diet

LFHC diet

Intervention Type DIETARY_SUPPLEMENT

low-fat, high-carbohydrate (LFHC) diet

Interventions

Learn about the drugs, procedures, or behavioral strategies being tested and how they are applied within this trial.

LCHF diet

low-carbohydrate, high-fat (LCHF)diet

Intervention Type DIETARY_SUPPLEMENT

LFHC diet

low-fat, high-carbohydrate (LFHC) diet

Intervention Type DIETARY_SUPPLEMENT

Eligibility Criteria

Check the participation requirements, including inclusion and exclusion rules, age limits, and whether healthy volunteers are accepted.

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
Minimum Eligible Age

18 Years

Maximum Eligible Age

50 Years

Eligible Sex

ALL

Accepts Healthy Volunteers

Yes

Sponsors

Meet the organizations funding or collaborating on the study and learn about their roles.

National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)

NIH

Sponsor Role lead

Responsible Party

Identify the individual or organization who holds primary responsibility for the study information submitted to regulators.

Responsibility Role SPONSOR

Principal Investigators

Learn about the lead researchers overseeing the trial and their institutional affiliations.

Kevin Hall, Ph.D.

Role: PRINCIPAL_INVESTIGATOR

National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)

Locations

Explore where the study is taking place and check the recruitment status at each participating site.

National Institutes of Health Clinical Center

Bethesda, Maryland, United States

Site Status

Countries

Review the countries where the study has at least one active or historical site.

United States

References

Explore related publications, articles, or registry entries linked to this study.

Jaime-Lara RB, Franks AT, Nawal N, Steck MC, Chao AM, Allen C, Brooks BE, Atkinson M, Courville AB, Guo J, Yang S, Marzouk M, Darcey VL, Chung S, Forde CG, Hall KD, Joseph PV. The Role of Diet and Hormones on Taste: Low Carb Compared With Low Fat Study Findings. Curr Dev Nutr. 2025 May 19;9(6):107467. doi: 10.1016/j.cdnut.2025.107467. eCollection 2025 Jun.

Reference Type DERIVED
PMID: 40606290 (View on PubMed)

Hengist A, Ong JA, McNeel K, Guo J, Hall KD. Imprecision nutrition? Intraindividual variability of glucose responses to duplicate presented meals in adults without diabetes. Am J Clin Nutr. 2025 Jan;121(1):74-82. doi: 10.1016/j.ajcnut.2024.10.007. Epub 2024 Dec 2.

Reference Type DERIVED
PMID: 39755436 (View on PubMed)

Sciarrillo CM, Guo J, Hengist A, Darcey VL, Hall KD. Diet order significantly affects energy balance for diets varying in macronutrients but not ultraprocessing in crossover studies without a washout period. Am J Clin Nutr. 2024 Oct;120(4):953-963. doi: 10.1016/j.ajcnut.2024.08.013. Epub 2024 Aug 18.

Reference Type DERIVED
PMID: 39163976 (View on PubMed)

Link VM, Subramanian P, Cheung F, Han KL, Stacy A, Chi L, Sellers BA, Koroleva G, Courville AB, Mistry S, Burns A, Apps R, Hall KD, Belkaid Y. Differential peripheral immune signatures elicited by vegan versus ketogenic diets in humans. Nat Med. 2024 Feb;30(2):560-572. doi: 10.1038/s41591-023-02761-2. Epub 2024 Jan 30.

Reference Type DERIVED
PMID: 38291301 (View on PubMed)

Sciarrillo CM, Guo J, Hengist A, Darcey VL, Hall KD. Diet order affects energy balance in randomized crossover feeding studies that vary in macronutrients but not ultra-processing. medRxiv [Preprint]. 2023 Oct 4:2023.10.03.23296501. doi: 10.1101/2023.10.03.23296501.

Reference Type DERIVED
PMID: 37986904 (View on PubMed)

O'Connor LE, Hall KD, Herrick KA, Reedy J, Chung ST, Stagliano M, Courville AB, Sinha R, Freedman ND, Hong HG, Albert PS, Loftfield E. Metabolomic Profiling of an Ultraprocessed Dietary Pattern in a Domiciled Randomized Controlled Crossover Feeding Trial. J Nutr. 2023 Aug;153(8):2181-2192. doi: 10.1016/j.tjnut.2023.06.003. Epub 2023 Jun 3.

Reference Type DERIVED
PMID: 37276937 (View on PubMed)

Hall KD, Guo J, Courville AB, Boring J, Brychta R, Chen KY, Darcey V, Forde CG, Gharib AM, Gallagher I, Howard R, Joseph PV, Milley L, Ouwerkerk R, Raisinger K, Rozga I, Schick A, Stagliano M, Torres S, Walter M, Walter P, Yang S, Chung ST. Effect of a plant-based, low-fat diet versus an animal-based, ketogenic diet on ad libitum energy intake. Nat Med. 2021 Feb;27(2):344-353. doi: 10.1038/s41591-020-01209-1. Epub 2021 Jan 21.

Reference Type DERIVED
PMID: 33479499 (View on PubMed)

Provided Documents

Download supplemental materials such as informed consent forms, study protocols, or participant manuals.

Document Type: Study Protocol and Statistical Analysis Plan

View Document

Related Links

Access external resources that provide additional context or updates about the study.

Other Identifiers

Review additional registry numbers or institutional identifiers associated with this trial.

19-DK-0067

Identifier Type: OTHER

Identifier Source: secondary_id

190067

Identifier Type: -

Identifier Source: org_study_id

More Related Trials

Additional clinical trials that may be relevant based on similarity analysis.

Precision Nutrition and Metabolic Function
NCT04131166 ACTIVE_NOT_RECRUITING NA
Body Weight and Carb Metabolism
NCT05330481 COMPLETED
Variations in Ketone Metabolism
NCT05924295 RECRUITING NA