NCT07175701

Ultra-processed Food-reducing Intervention and Continuous Glucose Monitoring

Effects of Ultra-processed Food Reduction Intervention on Postprandial Glucose and Glycemic Variability in Korean Young Adults: Study Protocol for the ULTRA-CGM Randomized Controlled Trial

• Status: Recruiting
• Phase: N/A
• Study type: Interventional
• Enrollment: 50 (estimated)
• Sponsor: Korea University · Academic / Other
• Sex: All
• Age: 20 Years – 39 Years
• Healthy volunteers: Accepted

Summary

The goal of this trial is to investigate whether reduction in ultra-processed food intake through dietary counseling and education can improve postprandial glucose responses and glycemic variability compared with a usual diet in young, healthy Korean adults aged 20-30 years. The main questions it aims to answer are: \- Does reducing ultra-processed food intake, while maintaining total energy intake and usual lifestyle behaviors, improve postprandial glucose and lower glycemic variability in healthy adults without diabetes? Participants will: * Undergo the 10-day pre-intervention monitoring period, during which each participant will wear a continuous glucose monitoring (CGM) device and concurrently report their daily dietary intakes (all food and beverage consumption) and other lifestyle behaviors (sleep, smoking, physical activity) * After the 10-day pre-intervention monitoring period, participants will be randomized to either intervention or control group * Intervention group: Participants will visit the research site to receive dietitian-led one-on-one nutrition education and personalized dietary counseling targeting reduction of ultra-processed food intake. Personalized diet counseling will be provided by study dietitian based on participant's records of dietary intakes during the 10-day pre-intervention monitoring period. * Control group: Participants will receive dietitian-led nutrition education and personalized dietary counseling based on the national dietary guidelines. * After the intervention, participants will undergo the 10-day post-intervention monitoring period, during which participants will wear a new CGM device for an additional 10 days and continue daily reporting of dietary intakes (all food and beverage consumptions) and lifestyle behaviors (sleep, smoking, physical activity).

Detailed description

The Ultra-Processed Food Reduction Intervention and Continuous Glucose Monitoring (ULTRA-CGM) trial is a parallel, two-arm randomized controlled trial designed to evaluate the effects of a ultra-processed food (UPF)-reducing dietary intervention on postprandial glucose responses and glycemic variability in young Korean adults (aged 20-39 years) using CGM devices. Participants will be randomly assigned to either a UPF-reducing intervention group or a control group maintaining their usual diet. We hypothesize that receiving the UPF-reducing dietary intervention will improve postprandial glucose responses and reduce glycemic variability compared with participants receiving standard dietary counseling based on national guidelines. The findings from this trial may provide experimental evidence on the metabolic effects of reducing UPF consumption and inform dietary strategies for diabetes prevention among younger adults.

Conditions

• Postprandial Glucose
• Glucose Levels
• Hyperglycemias

Interventions

Type	Name	Description
BEHAVIORAL	40-minute one-on-one dietary counseling and nutrition education aimed at reducing ultra-processed food consumption	Participants assigned to the intervention group receive a 40-minute one-on-one nutrition education session and personalized dietary counseling delivered by the study dietitian. The goals of these sessions are to reduce UPF consumption while maintaining total energy intake and usual lifestyle behaviors. All sessions follow a standardized protocol to ensure consistent delivery of the intervention. The study dietitian delivering the intervention receives training on the standardized protocol prior to participant enrollment.
BEHAVIORAL	Standard dietary counseling and nutrition education based on national guidelines	Participants assigned to the control group are also provided with a 40-minute one-on-one nutrition education session and personalized dietary counseling, but with different objectives. During these sessions, the national dietary guidelines are introduced using an educational leaflet distributed by the Ministry of Health and Welfare. The education session and counseling provided to the control group do not include any information on UPFs. After completion of the study, participants in the control group are provided with the same nutrition education materials on UPF reduction that are used in the intervention group.

Timeline

• Start date: 2025-10-11
• Primary completion: 2026-08-31
• Completion: 2026-08-31
• First posted: 2025-09-16
• Last updated: 2026-04-17

Locations

1 site across 1 country: South Korea