Ultra-Processed Foods, Palatability, Appetite, and Gastrointestinal Transit

NCT07600281 | Completed

• 1 other identifier: IRB-2024-450
• Study Type: interventional
• Target: 40
• Locations: 1 country
• Sites: 1

Brief Summary

The goal of this clinical trial is to learn how food processing level affects appetite and gastrointestinal transit time when meal palatability is changed. Participants will complete one screening visit and four test visits. During each test visit, participants will consume one of four meals that differ by food processing level and palatability: high-palatability ultra-processed food, low-palatability ultra-processed food, high-palatability non-ultra-processed food, or low-palatability non-ultra-processed food. The main questions this study aims to answer are whether food processing and palatability affect appetite sensations and gastrointestinal transit time. Participants will rate appetite sensations during each test visit and provide breath samples to measure gastrointestinal transit time.

Conditions

Appetite; Gastrointestinal Transit; Food Processing; Food Palatability; Eating Behavior

Keywords

Ultra-processed foods; Non-ultra-processed foods; Palatability; Appetite; Gastrointestinal transit time; Orocecal transit time; Hydrogen breath test; Lactulose; Visual analog scale; Bitter melon powder

Outcome Measures

Primary Outcomes (3)

• Orocecal Transit Time

  Orocecal transit time will be assessed using hydrogen analysis of end-alveolar breath samples collected after consumption of each test meal. Each test meal will contain lactulose as a marker of gastrointestinal transit time.

  During each test visit, up to 4.5 hours after meal consumption

• Appetite Sensations

  Appetite sensations, including hunger, fullness, desire to eat, amount participants could eat, and thirst, will be assessed using visual analog scales during each test visit after consumption of the assigned test meal every 30 minutes

  During each test visit, up to 4.5 hours after meal consumption

• Meal Palatability Ratings

  Meal palatability will be assessed using participant ratings of the appeal of each test meal during each study visit.

  During each test visit, up to 4.5 hours after meal consumption

Study Arms (4)

Palatable Ultra-Processed Food

EXPERIMENTAL

Participants will consume a palatable ultra-processed test meal during one study visit. The meal will be used to assess appetite sensations, palatability ratings, and gastrointestinal transit time.

Other: Palatable Ultra-Processed Food Meal

Unpalatable Ultra-Processed Food

EXPERIMENTAL

Participants will consume an unpalatable ultra-processed test meal during one study visit. Palatability will be reduced by adding bitter melon powder. The meal will be used to assess appetite sensations, palatability ratings, and gastrointestinal transit time.

Other: Unpalatable Ultra-Processed Food Meal

Palatable Non-Ultra-Processed Food

EXPERIMENTAL

Participants will consume a palatable non-ultra-processed test meal during one study visit. The meal will be used to assess appetite sensations, palatability ratings, and gastrointestinal transit time.

Other: Palatable Non-Ultra-Processed Food Meal

Unpalatable Non-Ultra-Processed Food

EXPERIMENTAL

Participants will consume a unpalatable non-ultra-processed test meal during one study visit. Palatability will be reduced by adding bitter melon powder. The meal will be used to assess appetite sensations, palatability ratings, and gastrointestinal transit time.

Other: Unpalatable Non-Ultra-Processed Food Meal

Interventions

Palatable Ultra-Processed Food Meal OTHER

Participants will consume a palatable ultra-processed test meal during one study visit. The meal will consist of commonly available ultra-processed food items and will be used to assess appetite sensations, meal palatability, and gastrointestinal transit time.

Palatable Ultra-Processed Food

Unpalatable Ultra-Processed Food Meal OTHER

Participants will consume an unpalatable ultra-processed test meal during one study visit. Palatability will be reduced by adding organic bitter melon powder to the ultra-processed meal. The meal will be used to assess appetite sensations, meal palatability, and gastrointestinal transit time.

Unpalatable Ultra-Processed Food

Palatable Non-Ultra-Processed Food Meal OTHER

Participants will consume a palatable non-ultra-processed test meal during one study visit. The meal will consist of commonly available non-ultra-processed food items and will be used to assess appetite sensations, meal palatability, and gastrointestinal transit time.

Palatable Non-Ultra-Processed Food

Unpalatable Non-Ultra-Processed Food Meal OTHER

Participants will consume an unpalatable non-ultra-processed test meal during one study visit. Palatability will be reduced by adding organic bitter melon powder to the non-ultra-processed meal. The meal will be used to assess appetite sensations, meal palatability, and gastrointestinal transit time.

Unpalatable Non-Ultra-Processed Food

Eligibility Criteria

• Age: 18 Years - 60 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64)

You may qualify if:

• Individuals aged 18 to 60 years.
• Any sex, gender, or orientation.
• Self-reported good health.
• No medication use.
• No allergies or food sensitivities to any of the foods used in the study.
• No anticipated change in physical activity during the study period.
• Willingness to complete all planned study activities, including the screening visit and four test visits.
• At screening, participants must rate the selected high-palatability foods between 60 and 90 on a 100-unit visual analog scale, where 100 = extremely palatable.
• At screening, participants must rate the selected low-palatability foods between 10 and 40 on a 100-unit visual analog scale.

You may not qualify if:

• Younger than 18 years or older than 60 years.
• Current medication use.
• Allergies or food sensitivities to any study foods.
• Not meeting the required palatability rating ranges during screening.
• Anticipated change in physical activity during the study period.
• Not self-reporting good health.
• Unwillingness or inability to complete the planned study activities.

Sponsors & Collaborators

• Purdue University: lead

Study Sites (1)

Purdue University

West Lafayette, Indiana, 47907, United States

Location

Related Publications (1)

• Hall KD, Ayuketah A, Brychta R, Cai H, Cassimatis T, Chen KY, Chung ST, Costa E, Courville A, Darcey V, Fletcher LA, Forde CG, Gharib AM, Guo J, Howard R, Joseph PV, McGehee S, Ouwerkerk R, Raisinger K, Rozga I, Stagliano M, Walter M, Walter PJ, Yang S, Zhou M. Ultra-Processed Diets Cause Excess Calorie Intake and Weight Gain: An Inpatient Randomized Controlled Trial of Ad Libitum Food Intake. Cell Metab. 2019 Jul 2;30(1):67-77.e3. doi: 10.1016/j.cmet.2019.05.008. Epub 2019 May 16.

  PMID: 31105044 BACKGROUND

MeSH Terms

Conditions

Feeding Behavior

Condition Hierarchy (Ancestors)

Behavior, Animal; Behavior

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: NONE
• Purpose: BASIC SCIENCE
• Intervention Model: CROSSOVER
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Distinguished Professor

Model Details: This is a within-subject crossover trial. Each participant will complete four test visits and consume each of the four test meals: high-palatability ultra-processed food, low-palatability ultra-processed food, high-palatability non-ultra-processed food, and low-palatability non-ultra-processed food. Test visits will be separated by at least one week.

Study Record Dates

• First Submitted: May 14, 2026
• First Posted: May 20, 2026
• Study Start: September 24, 2024
• Primary Completion: April 30, 2026
• Study Completion: April 30, 2026
• Last Updated: May 20, 2026

Record last verified: 2026-05

Data Sharing

• IPD Sharing: Will not share

Locations

US (1)