Ultra-processed Food Consumption and Health Pilot Study

NCT07318064 | Not Yet Recruiting

• 1 other identifier: 2025-063
• Study Type: interventional
• Target: 6
• Locations: 0 countries
• Sites: N/A

Brief 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. 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.

Conditions

Obesity & Overweight

Keywords

ultra-processed diet; precision nutrition; metabolomics; weight loss

Outcome Measures

Primary Outcomes (1)

• Body weight

  Body weight measured in kg

  Change from baseline to 14 days

Secondary Outcomes (18)

• Physical activity

  Change from baseline to 14 days

• Waist circumference

  Change from baseline to 14 days

• Total body fat

  Changes from baseline to 14 days

• Total fat-free mass

  Change from baseline to 14 days

• Twenty-four-hour interstitial glucose

  Continuously from baseline to 14 days

Study Arms (2)

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.

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.

Behavioral: Ultra-processed diet

Interventions

Purple Diet BEHAVIORAL

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.

Purple Diet

Ultra-processed diet BEHAVIORAL

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.

Ultra-processed Diet

Eligibility Criteria

• Age: 18 Years - 50 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64)

You may qualify if:

• 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

You may not qualify if:

• 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
• 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

Sponsors & Collaborators

• Pennington Biomedical Research Center: lead

MeSH Terms

Conditions

Obesity; Overweight; Weight Loss

Condition Hierarchy (Ancestors)

Overnutrition; Nutrition Disorders; Nutritional and Metabolic Diseases; Body Weight; Signs and Symptoms; Pathological Conditions, Signs and Symptoms; Body Weight Changes

Study Officials

• Peter T Katzmarzyk, PhD

  Pennington Biomedical Research Center

  PRINCIPAL INVESTIGATOR

Central Study Contacts

Peter T Katzmarzyk, PhD

CONTACT

225-763-2536; Peter.katzmarzyk@pbrc.edu

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: TRIPLE
• Who Masked: PARTICIPANT, INVESTIGATOR, OUTCOMES ASSESSOR
• Purpose: PREVENTION
• Intervention Model: CROSSOVER
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Professor

Study Record Dates

• First Submitted: December 19, 2025
• First Posted: January 5, 2026
• Study Start: February 1, 2026
• Primary Completion (Estimated): October 1, 2026
• Study Completion (Estimated): October 1, 2026
• Last Updated: January 6, 2026

Record last verified: 2026-01

Data Sharing

• IPD Sharing: Will share
• Shared Documents: STUDY PROTOCOL
• Time Frame: Data will be available indefinitely starting from the publication of the primary paper.
• Access Criteria: Data will be stored in the Pennington Biomedical Nutrition Obesity Research Center (NORC) Data and Biorepository. Data are available upon reasonable request to the repository manager.