Healthy DietNCT05290064
Effect of Ultra-processed Versus Unprocessed Diets on Energy Metabolism
A study testing Ultra-processed food, high energy density (UPF HL), Ultra-processed food, both low (UPF LL) and Ultra-processed food, both high (UPF HH) in people with Healthy Diet and Obesity, run by National Institutes of Health Clinical Center (CC) at 1 site in United States.
Trial summary
Protocol Number: 22DK0002 Title: Effects of Ultra-processed versus Unprocessed Diets on Energy Metabolism Background: Many diets worldwide include both processed and unprocessed foods. Researchers want to study the effects these foods have on a person s health. Read more about this study
- Who is it for?
- Ages 18 to 60 years
- Conditions the study is for
- Healthy Diet, Obesity
- What is being tested?
- Ultra-processed food, high energy density (UPF HL), Ultra-processed food, both low (UPF LL) and Ultra-processed food, both high (UPF HH)
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 38 participants
- Where
- 1 siteUnited States
- Study dates
- 24 Nov 2022to 15 Aug 2025
- Phase
- Interventional
- Are there results?
- Yes, posted in the registrySummary in the doctors' view
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 60 years
- All sexes
- No healthy volunteers
- Adult
Who may be able to join
- In order to be eligible to participate in this study, an individual must meet all of the following criteria:
- Provision of signed and dated informed consent form
- Adults age 18-60 years, male and female
- Weight stable (< +/- 5 % body weight change over past 6 months) as determined by volunteer report
- Body mass index (BMI) > =20 kg/m2
- Body weight > = 53 kg
- Able to complete daily bouts of stationary cycling at a moderate rate and intensity with a 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
- Willingness to comply with all study procedures and Lifestyle Considerations for the duration of the study per the discretion of the PI.
Who cannot join
- An individual who meets any of the following criteria will be excluded from participation in this study:
- Evidence of diseases or conditions that may influence appetite (e.g., cancer, diabetes, alterations of smell or taste post COVID-19), or other conditions at the discretion of the PI and/or study team).
- Taking prescription medications or other drugs that may influence appetite (including, but not limited to, diet/weight-loss medication or other medications at the discretion of the PI and/or study team)
- Positive pregnancy test or lactation as determined by volunteer report (women only)
- Participating in a regular exercise program (> 2h/week of vigorous activity) as determined by volunteer report
- Hematocrit < 37% (women only)
Show all 13Show fewer
- Hematocrit < 40% (men only)
- Caffeine consumption > 300 mg/day as determined by volunteer report
- Alcohol consumption > 3 drinks per day for men or > 2 drinks per day for women as determined by volunteer report
- Regular use of tobacco (smoking or chewing), amphetamines, cocaine, heroin, or marijuana over past 6 months as determined by volunteer report. Subjects may also be excluded based on a urine drug test.
- Psychological conditions as determined by volunteer report such as (but not limited to) eating disorders, depression, bipolar disorders, that would be incompatible with safe and successful participation in this study, as determined by investigators
- Volunteers with strict dietary concerns (e.g. vegetarian or kosher diet, food allergies) or a reported dislike of a significant fraction of the study foods
- Volunteers unwilling or unable to give informed consent
Trial locations and contacts
1 site in 1 country.
United States1 site
National Institutes of Health Clinical Center
Bethesda, Maryland, 20892
About this study
Protocol Number: 22DK0002
Title: Effects of Ultra-processed versus Unprocessed Diets on Energy Metabolism
Read more
Background:
Many diets worldwide include both processed and unprocessed foods. Researchers want to study the effects these foods have on a person s health.
Objective:
To study how different diets affect a person s health and metabolism.
Eligibility:
Adults aged 18 60 without diabetes who have stable weight and can exercise.
Design:
Participants will be screened with:
Medical history
Physical exam
Heart tests
Resting energy expenditure (to determine calorie needs)
Blood and urine tests
20-minute stationary bicycle session
Food, diet, and mental health questionnaires
Participants will stay at NIH for 4 weeks. They will receive 3 meals a day and may eat as little or as much as they want. The diet will change each week. Their weight will be recorded daily. They will ride a stationary bicycle daily. Each week, they will do the following:
Spend 1 day in a special room that assesses their metabolism
Have 24-hour urine collections
Give skin and fecal samples
Repeat some screening tests
Have scans to measure body fat
Complete computerized behavior tasks
Wear an activity monitor to track physical activity
Wear a glucose monitor. A sensor will be inserted under the skin with a small needle. It will be replaced weekly.
Take taste tests. They will swish water and flavored liquids around in their mouth and pick which ones had a non-neutral taste. They will also compare liquids for which ones taste better.
Participation will last for 4 weeks.
Sponsoring Institution: National Institute of Diabetes and Digestive and Kidney Diseases
...
Read the detailed description
This is a randomized crossover study of adult volunteers to determine the health effects of four different diets varying in non-beverage energy density, hyperpalatable foods, as well as the degree, extent, and purpose of processing according to the NOVA classification system.
Objectives/Endpoints:
Primary Aim:
To determine differences in health effects during four 1-week test diets.
Secondary Aims:
To determine differences in mean eating rate (grams per minute) and palatability of meals between the four 1-week test diets.
Exploratory Aims:
Several exploratory measurements are planned to help comprehensively phenotype the effects of the test diets and are intended to be hypothesis-generating.
- Conditions
- Healthy Diet, Obesity
- Being tested
- Ultra-processed food, high energy density (UPF HL), Ultra-processed food, both low (UPF LL), Ultra-processed food, both high (UPF HH), Unprocessed food diet (UNF LL)
- Keywords
- Body Weight, Food Intake, Fat, Calories, Body Mass Index
- Medical subject headings
- Obesity, Body Weight, Platelet Glycoprotein IV Deficiency
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Ultra-processed food, high energy density (UPF HL)Other
Ultra-processed diet that is high in non-beverage energy density and low in hyperpalatable foods
Ultra-processed food, both low (UPF LL)Other
Ultra-processed diet that is low in both non-beverage energy density and hyperpalatable foods
Ultra-processed food, both high (UPF HH)Other
Ultra-processed diet that is high in both non-beverage energy density and hyperpalatable foods
Unprocessed food diet (UNF LL)Other
Unprocessed diet that is low in both non-beverage energy density and hyperpalatable foods
| Study group | Role | What they receive |
|---|---|---|
| 1/UPF HH, UPF HL, UNF LL, UPF LL | Experimental | Four diets in the order specified Receives: Other: Ultra-processed food, high energy density (UPF HL); Other: Ultra-processed food, both low (UPF LL); Other: Ultra-processed food, both high (UPF HH); Other: Unprocessed food diet (UNF LL) |
| 2/ UPF HL, UPF LL, UPF HH, UNF LL | Experimental | Four diets in the order specified Receives: Other: Ultra-processed food, high energy density (UPF HL); Other: Ultra-processed food, both low (UPF LL); Other: Ultra-processed food, both high (UPF HH); Other: Unprocessed food diet (UNF LL) |
| 3/ UPF LL, UNF LL, UPF HL, UPF HH | Experimental | Four diets in the order specified Receives: Other: Ultra-processed food, high energy density (UPF HL); Other: Ultra-processed food, both low (UPF LL); Other: Ultra-processed food, both high (UPF HH); Other: Unprocessed food diet (UNF LL) |
| 4/ UNF LL, UPF HH, UPF LL, UPF HL | Experimental | Four diets in the order specified Receives: Other: Ultra-processed food, high energy density (UPF HL); Other: Ultra-processed food, both low (UPF LL); Other: Ultra-processed food, both high (UPF HH); Other: Unprocessed food diet (UNF LL) |
What is being measured
The primary outcome is the main question the study is designed to answer.
Energy Intake (kcal Per Day)
Energy intake averaged over 7 days for each diet, measured in kilocalories (kcal) per day. Primary comparisons will be between UPF HH \& UPF HL, UPF HL \& UPF LL, UPF LL \& UNF LL, UPF HH \& UNF LL.
Measured: Four 1-week diets
Secondary outcomes (2)
Meal Eating Rate (Grams Per Minute)
This will be determined by the measured duration of the meals along with the measured mass of food consumed.
Measured: Four 1-week diets
Meal Palatability
Meal Palatability will be measured via questionnaires using visual analogue scales. The range of VAS is 0-100, where 0 = "Not at all palatable" and 100 = "Extremely palatable"
Measured: Four 1-week diets
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted22 Mar 2022
- Study start24 Nov 2022
- Primary completion15 Aug 2025
- Study completion15 Aug 2025
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Posted resultsParticipant flow, outcome measures and adverse events reported by the sponsor.
- Other trials for Healthy DietStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Basic science
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- None (open label)
- Enrolment
- 38 participants (actual)
Sponsor and investigators
- Lead sponsor
- National Institutes of Health Clinical Center (CC)
- Sponsor type
- US National Institutes of Health
- Responsible party
- Sponsor
- Investigators
- Valerie L Darcey, Principal investigator, National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT05290064
- Sponsor's protocol ID
- 220002
- Other IDs
- 22-DK-0002
- Status last verified
- Jul 2026
- First submitted
- 19 Mar 2022
- Last updated
- 12 Aug 2026
- Results posted
- Yes, on ClinicalTrials.gov
- FDA-regulated drug
- No
- FDA-regulated device
- No
Study at a glance
From the registry record, last updated by the sponsor on 12 Aug 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Effect of Ultra-processed Versus Unprocessed Diets on Energy Metabolism
- ClinicalTrials.gov ID
- NCT05290064
- Acronym / sponsor ID
- 220002
- Conditions
- Healthy Diet, Obesity
- Keywords
- Body Weight, Food Intake, Fat, Calories, Body Mass Index
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 38 participants (actual)
- Lead sponsor
- National Institutes of Health Clinical Center (CC)US National Institutes of Health
- Collaborators
- National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
- Study start
- 24 Nov 2022 (actual)
- Primary completion
- 15 Aug 2025 (actual)
- Study completion
- 15 Aug 2025 (actual)
- First posted
- 22 Mar 2022 (actual)
- Results
- Posted 12 Aug 2026
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
Protocol Number: 22DK0002
Title: Effects of Ultra-processed versus Unprocessed Diets on Energy Metabolism
Background:
Many diets worldwide include both processed and unprocessed foods. Researchers want to study the effects these foods have on a person s health.
Objective:
To study how different diets affect a person s health and metabolism.
Eligibility:
Adults aged 18 60 without diabetes who have stable weight and can exercise.
Design:
Participants will be screened with:
Medical history
Physical exam
Heart tests
Resting energy expenditure (to determine calorie needs)
Blood and urine tests
20-minute stationary bicycle session
Food, diet, and mental health questionnaires
Participants will stay at NIH for 4 weeks. They will receive 3 meals a day and may eat as little or as much as they want. The diet will change each week. Their weight will be recorded daily. They will ride a stationary bicycle daily. Each week, they will do the following:
Spend 1 day in a special room that assesses their metabolism
Have 24-hour urine collections
Give skin and fecal samples
Repeat some screening tests
Have scans to measure body fat
Complete computerized behavior tasks
Wear an activity monitor to track physical activity
Wear a glucose monitor. A sensor will be inserted under the skin with a small needle. It will be replaced weekly.
Take taste tests. They will swish water and flavored liquids around in their mouth and pick which ones had a non-neutral taste. They will also compare liquids for which ones taste better.
Participation will last for 4 weeks.
Sponsoring Institution: National Institute of Diabetes and Digestive and Kidney Diseases
...
Detailed description
This is a randomized crossover study of adult volunteers to determine the health effects of four different diets varying in non-beverage energy density, hyperpalatable foods, as well as the degree, extent, and purpose of processing according to the NOVA classification system.
Objectives/Endpoints:
Primary Aim:
To determine differences in health effects during four 1-week test diets.
Secondary Aims:
To determine differences in mean eating rate (grams per minute) and palatability of meals between the four 1-week test diets.
Exploratory Aims:
Several exploratory measurements are planned to help comprehensively phenotype the effects of the test diets and are intended to be hypothesis-generating.
Study design
- Primary purpose
- Basic science
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- None (open label)
- Number of arms
- 4
| Arm | Type | Receives |
|---|---|---|
| 1/UPF HH, UPF HL, UNF LL, UPF LL | Experimental | Other: Ultra-processed food, high energy density (UPF HL), Other: Ultra-processed food, both low (UPF LL), Other: Ultra-processed food, both high (UPF HH), Other: Unprocessed food diet (UNF LL)Four diets in the order specified |
| 2/ UPF HL, UPF LL, UPF HH, UNF LL | Experimental | Other: Ultra-processed food, high energy density (UPF HL), Other: Ultra-processed food, both low (UPF LL), Other: Ultra-processed food, both high (UPF HH), Other: Unprocessed food diet (UNF LL)Four diets in the order specified |
| 3/ UPF LL, UNF LL, UPF HL, UPF HH | Experimental | Other: Ultra-processed food, high energy density (UPF HL), Other: Ultra-processed food, both low (UPF LL), Other: Ultra-processed food, both high (UPF HH), Other: Unprocessed food diet (UNF LL)Four diets in the order specified |
| 4/ UNF LL, UPF HH, UPF LL, UPF HL | Experimental | Other: Ultra-processed food, high energy density (UPF HL), Other: Ultra-processed food, both low (UPF LL), Other: Ultra-processed food, both high (UPF HH), Other: Unprocessed food diet (UNF LL)Four diets in the order specified |
Who may qualify
- Ages
- 18 to 60 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult
Key inclusion criteria (8 listed)
- In order to be eligible to participate in this study, an individual must meet all of the following criteria:
- Provision of signed and dated informed consent form
- Adults age 18-60 years, male and female
- Weight stable (< +/- 5 % body weight change over past 6 months) as determined by volunteer report
- Body mass index (BMI) > =20 kg/m2
Key exclusion criteria (13 listed)
- An individual who meets any of the following criteria will be excluded from participation in this study:
- Evidence of diseases or conditions that may influence appetite (e.g., cancer, diabetes, alterations of smell or taste post COVID-19), or other conditions at the discretion of the PI and/or study team).
- Taking prescription medications or other drugs that may influence appetite (including, but not limited to, diet/weight-loss medication or other medications at the discretion of the PI and/or study team)
- Positive pregnancy test or lactation as determined by volunteer report (women only)
- Participating in a regular exercise program (> 2h/week of vigorous activity) as determined by volunteer report
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Ultra-processed food, high energy density (UPF HL)Ultra-processed diet that is high in non-beverage energy density and low in hyperpalatable foods | Other | 1/UPF HH, UPF HL, UNF LL, UPF LL, 2/ UPF HL, UPF LL, UPF HH, UNF LL, 3/ UPF LL, UNF LL, UPF HL, UPF HH, 4/ UNF LL, UPF HH, UPF LL, UPF HL |
| Ultra-processed food, both low (UPF LL)Ultra-processed diet that is low in both non-beverage energy density and hyperpalatable foods | Other | 1/UPF HH, UPF HL, UNF LL, UPF LL, 2/ UPF HL, UPF LL, UPF HH, UNF LL, 3/ UPF LL, UNF LL, UPF HL, UPF HH, 4/ UNF LL, UPF HH, UPF LL, UPF HL |
| Ultra-processed food, both high (UPF HH)Ultra-processed diet that is high in both non-beverage energy density and hyperpalatable foods | Other | 1/UPF HH, UPF HL, UNF LL, UPF LL, 2/ UPF HL, UPF LL, UPF HH, UNF LL, 3/ UPF LL, UNF LL, UPF HL, UPF HH, 4/ UNF LL, UPF HH, UPF LL, UPF HL |
| Unprocessed food diet (UNF LL)Unprocessed diet that is low in both non-beverage energy density and hyperpalatable foods | Other | 1/UPF HH, UPF HL, UNF LL, UPF LL, 2/ UPF HL, UPF LL, UPF HH, UNF LL, 3/ UPF LL, UNF LL, UPF HL, UPF HH, 4/ UNF LL, UPF HH, UPF LL, UPF HL |
Primary outcome
Energy Intake (kcal Per Day)
Time frame: Four 1-week diets
Energy intake averaged over 7 days for each diet, measured in kilocalories (kcal) per day. Primary comparisons will be between UPF HH \& UPF HL, UPF HL \& UPF LL, UPF LL \& UNF LL, UPF HH \& UNF LL.
2 secondary outcomes
Meal Eating Rate (Grams Per Minute)
Time frame: Four 1-week diets
Meal Palatability
Time frame: Four 1-week diets
Results and safety
Loading the posted results from ClinicalTrials.gov…
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 12 Aug 2026.
- Posted resultsParticipant flow, baseline, all outcome measures and adverse events.
- NIH Clinical Center Detailed Web PageLink provided by the sponsor.
Related trials for Healthy Diet
Not yet recruiting
Testing a Smartphone App to Support a Mediterranean Diet and Strength Exercise
Treatment Adherence and Compliance, Resistance Exercise
Recruiting
Whole Food for Families: A Pilot RCT of a Dietary Guidelines-Based Intervention to Prevent Type 2 Diabetes
PreDiabetes, Diet, Healthy
Recruiting
The Sleep2BWell Trial
Blood Pressure, Sleep Health
Enrolling by invitation
MTM2MTG Pilot Ancillary Study
Diet, Healthy, HbA1c
RecruitingPhase 1
Developing Biomarkers of Dietary Intake: Dose Dependent Measurement of Sugar Intake
Diet Therapy, Healthy Volunteers
Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Valerie L Darcey principal investigator
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Ultra-processed food, high energy density (UPF HL), Ultra-processed food, both low (UPF LL) and Ultra-processed food, both high (UPF HH) in people with Healthy Diet and Obesity, run by National Institutes of Health Clinical Center (CC) at 1 site in United States.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 8 inclusion and 13 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 12 Aug 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
Yes. Results are posted in the registry (first posted 12 Aug 2026). A summary is in the For doctors view, and the full results are on ClinicalTrials.gov.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Energy Intake (kcal Per Day) (time frame: Four 1-week diets). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 12 Aug 2026; AzTrials last refreshed its copy on 7 Nov 2026.