NCT07318064

Ultra-processed Food Consumption and Health Pilot Study

• Status: Not Yet Recruiting
• Phase: N/A
• Study type: Interventional
• Enrollment: 6 (estimated)
• Sponsor: Pennington Biomedical Research Center · Academic / Other
• Sex: All
• Age: 18 Years – 50 Years
• Healthy volunteers: Accepted

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.

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

Interventions

Type	Name	Description
BEHAVIORAL	Purple Diet	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.
BEHAVIORAL	Ultra-processed diet	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.

Timeline

• Start date: 2026-02-01
• Primary completion: 2026-10-01
• Completion: 2026-10-01
• First posted: 2026-01-05
• Last updated: 2026-01-06