Obesity & OverweightULTRA PIlotNCT07318064
Ultra-processed Food Consumption and Health Pilot Study
A study testing Purple Diet and Ultra-processed diet in people with Obesity & Overweight, run by Pennington Biomedical Research Center at 1 site in United States.
Trial summary
The objective of this study is to explore the effects of two dietary conditions (UPF-diet and typical American diet) on a number of clinical and metabolic outcomes in order to derive sample size estimates for a larger trial and to determine the feasibility of the study approach. Read more about this study
- Who is it for?
- Ages 18 to 50 yearsHealthy volunteers can take part
- Conditions the study is for
- Obesity & Overweight
- What is being tested?
- Purple Diet and Ultra-processed diet
- Type of treatment
- Lifestyle or therapy programme
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 6 participants
- Where
- 1 siteUnited States
- Study dates
- 11 Mar 2026to 1 Oct 2026
- Phase
- Interventional
- Are there results?
- Not yet: the study is under way
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 50 years
- All sexes
- Healthy volunteers accepted
- Adult
Who may be able to join
- Overweight or obesity (BMI 25-50 kg/m2)
- Willingness to accept group assignment and provide outcome measures
- Premenopausal (women only)
- Be able to communicate (oral and written) in English
- Be able to provide informed consent
Who cannot join
- Recent weight loss (≥10 pounds in the last six months)
- On a regimen of medications (weight loss or otherwise) that can affect weight or diabetes outcomes for less than 3 months (GLP1 medications allowed if weight stable and on stable dose for >=3 months)
- Given birth within the past year or is currently pregnant or breastfeeding
- Past bariatric surgery (<10 years) - all types
- Disease/condition that is life threatening or can interfere with or be aggravated by weight change
- Dementia, psychiatric illness, or substance abuse that may interfere with adherence
Show all 19Show fewer
- Current or history of a clinically diagnosed eating disorder, including anorexia nervosa or bulimia nervosa
- Type 1 or type 2 diabetes
- Uncontrolled gastrointestinal disorders including chronic malabsorptive conditions, peptic ulcer disease, Crohn's disease, chronic diarrhea or active gallbladder disease
- Current cancer or cancer treatment, or a history of cancer or cancer treatment within the last 3 years. Exceptions include 1) successfully resected non-melanoma carcinoma of the skin, 2) basal or squamous cell skin cancer, 3) stage 0 non-invasive carcinoma of the cervix, 4) stage 0 non-invasive prostate cancer
- History of kidney or liver disease or malnutrition that in investigator judgment should exclude participation
- Hemoglobinopathy that interferes with measurement of HbA1c
- Class II or higher congestive heart failure
- Unstable heart disease
- Blood pressure ≥160/100 mm Hg
- Thyroid disease for which the participant is untreated or has had treatment changed within the last 6 weeks.
- Unwilling to stop alcohol intake during study participation
- Current smoker or other type of tobacco user (chewing tobacco, vaping, etc.)
- Any other condition or factor which in the opinion of the study physician or investigator makes it inadvisable for the candidate to participate in the trial
Trial locations and contacts
1 site in 1 country.
United States1 site
Pennington Biomedical Research Center
Baton Rouge, Louisiana, 70810
About this study
The objective of this study is to explore the effects of two dietary conditions (UPF-diet and typical American diet) on a number of clinical and metabolic outcomes in order to derive sample size estimates for a larger trial and to determine the feasibility of the study approach.
This study is an out-patient cross-over trial comparing the Nutrition for Precision Health (NPH) purple diet (American Diet) and a diet high in ultra-processed foods (UPF diet) for two weeks in which participants will be randomized to the order of the diets.
Read more
Specific Aim 1: Determine the feasibility of recruiting, enrolling and assessing participants in a randomized trial comparing a UPF diet with the standard American diet. Feasibility will be assessed by the achievement of study goals (i.e., sample size; completeness of study data).
Specific Aim 2: Derive sample size estimates for future trials based on the mean effects and associated variances obtained in the pilot study.
Read the detailed description
The investigators will conduct an out-patient cross-over trial comparing the Nutrition for Precision Health (NPH) purple diet and a diet high in ultra-processed foods (UPF diet) with participants randomized equally to one of two conditions. Assessments of study outcomes will be conducted at baseline prior to randomization, and pre- and post- each dietary condition. The overarching aim is to determine the feasibility of the study approach, and to explore the effects of the dietary conditions on a number of clinical and metabolic outcomes.
Participants in this study will be 6 adults (both males and females) recruited from the community. Participants will receive each dietary condition for 14 days, with at least a 14-day wash-out period between conditions. The order of the conditions will be randomized.
Participants in both intervention conditions will be provided with meals and snacks prepared by the Pennington Biomedical Metabolic Kitchen. The total daily kilocalories, energy density, and macronutrient content of the two diets presented to the participants will be equivalent across the two conditions. Participants will be asked to consume only the foods provided according to a daily menu (including up to 2 cups of coffee or tea), water, and up to 12 oz. of artificially-sweetened beverages, and to adhere to their other usual routines (e.g., exercise, sleep, medication use) throughout the study.
Both diets will be isocaloric and will be provided using 3-day cycle menus, prepared by the Metabolic Kitchen. Menus will provide 3 meals and at least one snack. Participants will have some flexibility to distribute their meals and snacks across each day according to their preference. For menu planning, a 2100 kcal/d diet with scaled adjustments for individual energy needs will be planned. Templates will be developed that consist of 1600kcal, 2100kcal, 2600kcal, 3200kcal, and 3700kcal menus; 100 or 200 kcal foods that conform to the diet pattern and macronutrient profile will be added to the menu template (1600, 2100, 2600, 3200, or 3700 kcal) to deliver energy to the nearest hundred-kcal of estimated energy needs. These foods will also be added or removed from menus in cases of sustained weight loss or weight gain.
Participants will pick up study meals two to three times per week and will be provided with a 2 to 4-day meal supply at each pick-up. Meals will be assembled in advance of participant pick up and according to dietary intervention assignment, energy requirements and the allowed substitutions for food preferences. At the time of food dispensing, the participant's identity will be verified to match the provided meals. Meals will be packaged in a cooler for temperature-controlled transport along with instructions for retherming as needed.
The study outcomes will be collected immediately prior to and after each dietary condition.
- Conditions
- Obesity & Overweight
- Being tested
- Purple Diet, Ultra-processed diet
- Keywords
- ultra-processed diet, precision nutrition, metabolomics, weight loss
- Medical subject headings
- Obesity, Overweight, Weight Loss
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Purple DietBehavioural
The Purple Diet is modeled after a typical American diet which is popular, widely available, and lower in cost compared to other diets. However, the diet is high in total fat, and particularly in saturated fat, with consumption far exceeding 10% of total energy intake. Intake of added sugars also far exceeds the recommended limits.
Ultra-processed dietBehavioural
The ultra-processed food (UPF) diet is designed to contain approximately 75% of energy from ultra-processed foods. Foods and ingredients in the ultra-processed diet consist of those defined in the NOVA classification as "ultra-processed" (group 4 of the classification). The NOVA classification groups foods according to the nature, extent and purpose of the industrial processing they undergo.10 In the NOVA classification, ultra-processed foods include such things as soft drinks, packaged snacks, reconstituted meat products and pre-prepared frozen dishes, and are made mostly or entirely from substances derived from foods and additives, with little if any unprocessed foods.
| Study group | Role | What they receive |
|---|---|---|
| Purple Diet | Active comparator | The Purple Diet is modeled after a typical American diet which is popular, widely available, and lower in cost compared to other diets. However, the diet is high in total fat, and particularly in saturated fat, with consumption far exceeding 10% of total energy intake. Intake of added sugars also far exceeds the recommended limits. The Purple Diet has been used in the Nutrition for Precision Health study. Receives: Behavioral: Purple Diet |
| Ultra-processed Diet | Experimental | The ultra-processed (UPF) diet is designed to contain approximately 75% of energy from ultra-processed foods. Foods and ingredients in the ultra-processed diet consist of those defined in the NOVA classification as "ultra-processed" (group 4 of the classification). The NOVA classification groups foods according to the nature, extent and purpose of the industrial processing they undergo.10 In the NOVA classification, ultra-processed foods include such things as soft drinks, packaged snacks, reconstituted meat products and pre-prepared frozen dishes, and are made mostly or entirely from substances derived from foods and additives, with little if any unprocessed foods. Receives: Behavioral: Ultra-processed diet |
What is being measured
The primary outcome is the main question the study is designed to answer.
Body weight
Body weight measured in kg
Measured: Change from baseline to 14 days
Secondary outcomes (18)
Physical activity
Physical activity measured using the International Physical Activity Questionnaire - Short Form (IPAQ-SF)
Measured: Change from baseline to 14 days
Waist circumference
Waist circumference measured in cm
Measured: Change from baseline to 14 days
Total body fat
Total body fat in kg measured using Dual-Energy X-Ray Absorptiometry (DXA)
Measured: Changes from baseline to 14 days
Total fat-free mass
Fat free mass in kg measured using Dual-Energy X-ray Absorptiometry (DXA)
Measured: Change from baseline to 14 days
Twenty-four-hour interstitial glucose
Twenty-four-hour interstitial glucose will be measured using continuous glucose monitoring
Measured: Continuously from baseline to 14 days
Systolic blood pressure
Resting systolic blood pressure will be measured in mmHg
Measured: Change from baseline to 14 days
Diastolic blood pressure
Resting diastolic blood pressure measured in mmHg
Measured: Change from baseline to 14 days
Total cholesterol
Total cholesterol measured in mg/dL
Measured: Change from baseline to 14 days
Triglycerides
Triglycerides measured in mg/dL
Measured: Change from baseline to 14 days
HDL-cholesterol
HDL-cholesterol measured in mg/dL
Measured: Change from baseline to 14 days
LDL-cholesterol
LDL-cholesterol measured in mg/dL
Measured: Change from baseline to 14 days
Glucose
Fasting glucose measured in mg/dL
Measured: Change from baseline to 14 days
Insulin
Fasting insulin measured in mg/dL
Measured: Change from baseline to 14 days
HbA1c
HbA1c measured in %
Measured: Change from baseline to 14 days
Appetite
Appetite ratings (hunger/fullness/desire to eat) will be measured using visual analog scales.
Measured: Change from baseline to 14 days
Cognitive restraint
Cognitive restraint will be measured using the three-factor eating Questionnaire (TFEQ)
Measured: Change from baseline to 14 days
Disinhibition
Disinhibition will be measured using the Three-Factor Eating Questionnaire (TFEQ)
Measured: Change from baseline to 14 days
Hunger
Hunger will be measured using the Three-Factor Eating Questionnaire (TFEQ)
Measured: Change from baseline to 14 days
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted5 Jan 2026
- Study start11 Mar 2026
- Primary completion1 Oct 2026 (estimated)
- Study completion1 Oct 2026 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Obesity & OverweightStudies 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
- Prevention
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- Triple blind
- Who is masked
- Participant, Investigator, Outcomes assessor
- Enrolment
- 6 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Pennington Biomedical Research Center
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Peter T. Katzmarzyk, Pennington Biomedical Research Center
- Investigators
- Peter T Katzmarzyk, PhD, Principal investigator, Pennington Biomedical Research Center
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07318064
- Sponsor's protocol ID
- 2025-063
- Acronym
- ULTRA PIlot
- Status last verified
- Jun 2026
- First submitted
- 19 Dec 2025
- Last updated
- 29 Jun 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Yes: Raw deidentified data on the primary and secondary outcome measures collected during the trial will be available.
Study at a glance
From the registry record, last updated by the sponsor on 29 Jun 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Ultra-processed Food Consumption and Health Pilot Study
- ClinicalTrials.gov ID
- NCT07318064
- Acronym / sponsor ID
- ULTRA PIlot / 2025-063
- Conditions
- Obesity & Overweight
- Keywords
- ultra-processed diet, precision nutrition, metabolomics, weight loss
- Study type
- Interventional
- Recruitment status
- Active, not recruiting
- Enrolment
- 6 participants (estimated)
- Lead sponsor
- Pennington Biomedical Research CenterUniversity, hospital or other
- Study start
- 11 Mar 2026 (actual)
- Primary completion
- 1 Oct 2026 (estimated)
- Study completion
- 1 Oct 2026 (estimated)
- First posted
- 5 Jan 2026 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
The objective of this study is to explore the effects of two dietary conditions (UPF-diet and typical American diet) on a number of clinical and metabolic outcomes in order to derive sample size estimates for a larger trial and to determine the feasibility of the study approach.
This study is an out-patient cross-over trial comparing the Nutrition for Precision Health (NPH) purple diet (American Diet) and a diet high in ultra-processed foods (UPF diet) for two weeks in which participants will be randomized to the order of the diets.
Specific Aim 1: Determine the feasibility of recruiting, enrolling and assessing participants in a randomized trial comparing a UPF diet with the standard American diet. Feasibility will be assessed by the achievement of study goals (i.e., sample size; completeness of study data).
Specific Aim 2: Derive sample size estimates for future trials based on the mean effects and associated variances obtained in the pilot study.
Detailed description
The investigators will conduct an out-patient cross-over trial comparing the Nutrition for Precision Health (NPH) purple diet and a diet high in ultra-processed foods (UPF diet) with participants randomized equally to one of two conditions. Assessments of study outcomes will be conducted at baseline prior to randomization, and pre- and post- each dietary condition. The overarching aim is to determine the feasibility of the study approach, and to explore the effects of the dietary conditions on a number of clinical and metabolic outcomes.
Participants in this study will be 6 adults (both males and females) recruited from the community. Participants will receive each dietary condition for 14 days, with at least a 14-day wash-out period between conditions. The order of the conditions will be randomized.
Participants in both intervention conditions will be provided with meals and snacks prepared by the Pennington Biomedical Metabolic Kitchen. The total daily kilocalories, energy density, and macronutrient content of the two diets presented to the participants will be equivalent across the two conditions. Participants will be asked to consume only the foods provided according to a daily menu (including up to 2 cups of coffee or tea), water, and up to 12 oz. of artificially-sweetened beverages, and to adhere to their other usual routines (e.g., exercise, sleep, medication use) throughout the study.
Both diets will be isocaloric and will be provided using 3-day cycle menus, prepared by the Metabolic Kitchen. Menus will provide 3 meals and at least one snack. Participants will have some flexibility to distribute their meals and snacks across each day according to their preference. For menu planning, a 2100 kcal/d diet with scaled adjustments for individual energy needs will be planned. Templates will be developed that consist of 1600kcal, 2100kcal, 2600kcal, 3200kcal, and 3700kcal menus; 100 or 200 kcal foods that conform to the diet pattern and macronutrient profile will be added to the menu template (1600, 2100, 2600, 3200, or 3700 kcal) to deliver energy to the nearest hundred-kcal of estimated energy needs. These foods will also be added or removed from menus in cases of sustained weight loss or weight gain.
Participants will pick up study meals two to three times per week and will be provided with a 2 to 4-day meal supply at each pick-up. Meals will be assembled in advance of participant pick up and according to dietary intervention assignment, energy requirements and the allowed substitutions for food preferences. At the time of food dispensing, the participant's identity will be verified to match the provided meals. Meals will be packaged in a cooler for temperature-controlled transport along with instructions for retherming as needed.
The study outcomes will be collected immediately prior to and after each dietary condition.
Study design
- Primary purpose
- Prevention
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- Triple blind (participant, investigator, outcomes assessor)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Purple Diet | Active comparator | Behavioral: Purple DietThe Purple Diet is modeled after a typical American diet which is popular, widely available, and lower in cost compared to other diets. However, the diet is high in total fat, and particularly in saturated fat, with consumption far exceeding 10% of total energy intake. Intake of added sugars also far exceeds the recommended limits. The Purple Diet has been used in the Nutrition for Precision Health study. |
| Ultra-processed Diet | Experimental | Behavioral: Ultra-processed dietThe ultra-processed (UPF) diet is designed to contain approximately 75% of energy from ultra-processed foods. Foods and ingredients in the ultra-processed diet consist of those defined in the NOVA classification as "ultra-processed" (group 4 of the classification). The NOVA classification groups foods according to the nature, extent and purpose of the industrial processing they undergo.10 In the NOVA classification, ultra-processed foods include such things as soft drinks, packaged snacks, reconstituted meat products and pre-prepared frozen dishes, and are made mostly or entirely from substances derived from foods and additives, with little if any unprocessed foods. |
Who may qualify
- Ages
- 18 to 50 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult
Key inclusion criteria (5 listed)
- Overweight or obesity (BMI 25-50 kg/m2)
- Willingness to accept group assignment and provide outcome measures
- Premenopausal (women only)
- Be able to communicate (oral and written) in English
- Be able to provide informed consent
Key exclusion criteria (19 listed)
- Recent weight loss (≥10 pounds in the last six months)
- On a regimen of medications (weight loss or otherwise) that can affect weight or diabetes outcomes for less than 3 months (GLP1 medications allowed if weight stable and on stable dose for >=3 months)
- Given birth within the past year or is currently pregnant or breastfeeding
- Past bariatric surgery (<10 years) - all types
- Disease/condition that is life threatening or can interfere with or be aggravated by weight change
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 |
|---|---|---|
| Purple DietThe Purple Diet is modeled after a typical American diet which is popular, widely available, and lower in cost compared to other diets. However, the diet is high in total fat, and particularly in saturated fat, with consumption far exceeding 10% of total energy intake. Intake of added sugars also far exceeds the recommended limits. | Behavioural | Purple Diet |
| Ultra-processed dietThe ultra-processed food (UPF) diet is designed to contain approximately 75% of energy from ultra-processed foods. Foods and ingredients in the ultra-processed diet consist of those defined in the NOVA classification as "ultra-processed" (group 4 of the classification). The NOVA classification groups foods according to the nature, extent and purpose of the industrial processing they undergo.10 In the NOVA classification, ultra-processed foods include such things as soft drinks, packaged snacks, reconstituted meat products and pre-prepared frozen dishes, and are made mostly or entirely from substances derived from foods and additives, with little if any unprocessed foods. | Behavioural | Ultra-processed Diet |
Primary outcome
Body weight
Time frame: Change from baseline to 14 days
Body weight measured in kg
18 secondary outcomes
Physical activity
Time frame: Change from baseline to 14 days
Waist circumference
Time frame: Change from baseline to 14 days
Total body fat
Time frame: Changes from baseline to 14 days
Total fat-free mass
Time frame: Change from baseline to 14 days
Twenty-four-hour interstitial glucose
Time frame: Continuously from baseline to 14 days
Systolic blood pressure
Time frame: Change from baseline to 14 days
Diastolic blood pressure
Time frame: Change from baseline to 14 days
Total cholesterol
Time frame: Change from baseline to 14 days
Triglycerides
Time frame: Change from baseline to 14 days
HDL-cholesterol
Time frame: Change from baseline to 14 days
LDL-cholesterol
Time frame: Change from baseline to 14 days
Glucose
Time frame: Change from baseline to 14 days
Insulin
Time frame: Change from baseline to 14 days
HbA1c
Time frame: Change from baseline to 14 days
Appetite
Time frame: Change from baseline to 14 days
Cognitive restraint
Time frame: Change from baseline to 14 days
Disinhibition
Time frame: Change from baseline to 14 days
Hunger
Time frame: Change from baseline to 14 days
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 29 Jun 2026.
- Individual participant dataSharing planned: Yes. Raw deidentified data on the primary and secondary outcome measures collected during the trial will be available.
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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.
Peter T Katzmarzyk, PhD principal investigator
Pennington Biomedical Research Center
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Purple Diet and Ultra-processed diet in people with Obesity & Overweight, run by Pennington Biomedical Research Center 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 5 inclusion and 19 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: under way, not looking for participants, as of the sponsor's last update on 29 Jun 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?
This study is still under way. Results are not available in the source record yet.
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?
Body weight (time frame: Change from baseline to 14 days). 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 29 Jun 2026.