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Postprandial GlucoseULTRA-CGMNCT07175701

Ultra-processed Food-reducing Intervention and Continuous Glucose Monitoring

A study testing 40-minute one-on-one dietary counseling and nutrition education aimed at reducing ultra-processed food consumption and Standard dietary counseling and nutrition education based on national guidelines in people with Postprandial Glucose and Glucose Levels, run by Korea University at 1 site in South Korea.

Recruiting

Looking for participants now. Contact the study team or a site below to ask about taking part.

Sites and contacts
Official record
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Trial 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. Read more about this study

Who is it for?
Ages 20 to 39 yearsHealthy volunteers can take part
What is being tested?
40-minute one-on-one dietary counseling and nutrition education aimed at reducing ultra-processed food consumption and Standard dietary counseling and nutrition education based on national guidelines
Could I receive a placebo?
No, everyone receives an active treatment
How many people
50 participants
Where
1 siteSouth Korea
Study dates
11 Oct 2025to 31 Aug 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 20 to 39 years
  • All sexes
  • Healthy volunteers accepted
  • Adult

Who may be able to join

  • Korean adults aged 20-39 years
  • Not currently pregnant
  • No personal history of diabetes or other glucose-related conditions
  • Consume ≥25% of daily energy intake from UPFs, as assessed by an online, self-administered semi-quantitative screening food frequency questionnaire (FFQ)
  • No restriction on wearing a CGM device
  • No increased risk of bleeding
  • No prior adverse reaction to CGM devices
  • Willingness to participate in follow-up assessments

Who cannot join

  • Unable to maintain continuous follow-up during the study period (e.g., due to special plans such as traveling)
  • Planning to follow a special or restrictive diet (e.g., for weight loss) during the study period

Trial locations and contacts

1 site in 1 country. Contact the study team or a site near you to ask about taking part.

Yujin Kim, BSN contact

+82-10-8712-9763

iamyujin@korea.ac.kr

South Korea1 site, 1 recruiting

  • Health Promotion Lab, College of Health Science, Korea University

    Seoul, Seoul, 02841

    Yujin Kim, BSN, +82-10-8712-9763, iamyujin@korea.ac.kr

    Hannah Oh, ScD

    Recruiting

Other trials in South Korea

About this study

Official title: 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

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?
Read more

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).
Read the 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.

Being tested
40-minute one-on-one dietary counseling and nutrition education aimed at reducing ultra-processed food consumption, Standard dietary counseling and nutrition education based on national guidelines
Keywords
ultra-processed food, continuous glucose monitoring, processed food, glucose, glycemic variability, glycemic control, hyperglycemia, glucose intolerance, Food Additives, flavoring agents, sweetening agents, non-nutritive sweeteners, nutritive sweeteners, high fructose corn syrup, food coloring agents, food preservatives
Medical subject headings
Hyperglycemia, Glucose Intolerance

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • 40-minute one-on-one dietary counseling and nutrition education aimed at reducing ultra-processed food consumptionBehavioural

    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.

  • Standard dietary counseling and nutrition education based on national guidelinesBehavioural

    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.

Study groups in NCT07175701
Study groupRoleWhat they receive
Intervention groupExperimentalParticipants will be randomly assigned to the intervention group using block randomization with a 1:1 allocation ratio.
Receives: Behavioral: 40-minute one-on-one dietary counseling and nutrition education aimed at reducing ultra-processed food consumption
Control groupActive comparatorParticipants will be randomly assigned to the control group using block randomization with a 1:1 allocation ratio.
Receives: Behavioral: Standard dietary counseling and nutrition education based on national guidelines

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Change in postprandial glucose responses

    The primary outcome of this study is the change in postprandial glucose responses from the baseline monitoring period to the post-intervention monitoring period. Postprandial glucose responses are assessed using CGM and quantified as the incremental area under the curve (iAUC) over 2 hours following each meal. Higher iAUC values indicate greater postprandial glucose excursions.

    For each meal, iAUC is calculated as the area under the curve above the baseline level over the 2-hour postprandial period, using the trapezoidal rule. The baseline glucose level is defined as the mean glucose value in the 5 minutes immediately preceding meal consumption. For overlapping meals, the iAUC for the first meal is calculated from its start until 2 hours after, and overlapping periods are excluded from subsequent meals' iAUC to ensure each glucose excursion is counted once.

    Measured: Change in mean values from the baseline monitoring period (10-day period before the intervention) to the post-intervention monitoring period (10-day period immediately following the intervention)

Secondary outcomes (15)

  1. Change in coefficient of variation (CV)

    CV indicates relative glycemic variability and is calculated as the standard deviation of glucose measurements assessed using CGM divided by the mean glucose level.

    Measured: Change in mean values from the baseline monitoring period (10-day period before the intervention) to the post-intervention monitoring period (10-day period immediately following the intervention)

  2. Change in standard deviation (mg/dL)

    Standard deviation represents the absolute magnitude of glycemic variability, reflecting the dispersion of glucose values over time, assessed using CGM.

    Measured: Change in mean values from the baseline monitoring period (10-day period before the intervention) to the post-intervention monitoring period (10-day period immediately following the intervention)

  3. Change in mean amplitude of glycemic excursions (MAGE)

    Mean amplitude of glycemic excursions represents the mean amplitude of major glucose excursions. It is calculate by mean height of glycemic excursions (peaks and nadirs) that exceed one SD of the mean glucose over a 24-hour period.

    Measured: Change in mean values from the baseline monitoring period (10-day period before the intervention) to the post-intervention monitoring period (10-day period immediately following the intervention)

  4. Change in glucose spike frequency

    Glucose spike frequency quantifies the number of distinct glucose excursions above 140 mg/dL, providing an additional measure of postprandial hyperglycemia.

    Measured: Change in mean values from the baseline monitoring period (10-day period before the intervention) to the post-intervention monitoring period (10-day period immediately following the intervention)

  5. Change in time-in-range (%)

    Time-in-range represents the percentage of time spent within the consensus target glucose range of 70-180 mg/dL, as defined by international continuous glucose monitoring consensus recommendations.

    Measured: Change in mean values from the baseline monitoring period (10-day period before the intervention) to the post-intervention monitoring period (10-day period immediately following the intervention)

  6. Change in time-in-tight-range (%)

    Time-in-tight-range represents the percentage of time spent within the tighter target range of 70-140 mg/dL. Because participants are healthy young adults, time-in-tight-range 70-140 mg/dL is considered.

    Measured: Change in mean values from the baseline monitoring period (10-day period before the intervention) to the post-intervention monitoring period (10-day period immediately following the intervention)

  7. Change in time-above-range (%)

    Time-above-range represents the percentage of time spent with glucose levels above 180 mg/dL or 140 mg/dL. Because participants are healthy young adults, time-above-range 140 mg/dL is considered.

    Measured: Change in mean values from the baseline monitoring period (10-day period before the intervention) to the post-intervention monitoring period (10-day period immediately following the intervention)

  8. Change in time-below-range (%)

    Time-below-range represents the percentage of time spent with glucose levels below 70 mg/dL

    Measured: Change in mean values from the baseline monitoring period (10-day period before the intervention) to the post-intervention monitoring period (10-day period immediately following the intervention)

  9. Change in body weight (kg)

    Body weight will be directly measured by study staff to assess overall adiposity.

    Measured: Change from study enrollment (day 1) to study completion (day 23; 10 days after the intervention)

  10. Change in waist circumference (cm)

    Waist circumference will be directly measured by study staff to assess central adiposity.

    Measured: Change from study enrollment (day 1) to study completion (day 23; 10 days after the intervention)

  11. Change in fat mass (kg)

    Fat mass will be measured using a bioelectrical impedance analyzer (BIA) (InBody 270S; InBody Co., Ltd, Seoul, Korea).

    Measured: Change from study enrollment (day 1) to study completion (day 23; 10 days after the intervention)

  12. Change in muscle mass (kg)

    Muscle mass will be measured using a bioelectrical impedance analyzer (BIA) (InBody 270S; InBody Co., Ltd, Seoul, Korea).

    Measured: Change from study enrollment (day 1) to study completion (day 23; 10 days after the intervention)

  13. Change in percentage of body fat (%)

    Percentage of body fat will be measured using a bioelectrical impedance analyzer (BIA) (InBody 270S; InBody Co., Ltd, Seoul, Korea).

    Measured: Change from study enrollment (day 1) to study completion (day 23; 10 days after the intervention)

  14. Change in blood pressure measurements (mmHg)

    Blood pressures measurements, including both systolic and diastolic values, are measured to capture potential cardiometabolic effects of the intervention. Blood pressure is measured by a trained study nurse (a registered nurse) on the upper arm using an automated blood pressure monitoring device (WatchBP office Target BP3MD1-4; Microlife AG, Switzerland) while participants are seated and at rest. The mean of three consecutive measurements is used for analysis.

    Measured: Change from study enrollment (day 1) to study completion (day 23; 10 days after the intervention)

  15. Change in handgrip strength (kg)

    Handgrip strength is assessed as a marker of muscular strength and functional status. Handgrip strength is assessed using a handgrip dynamometer (T.K.K.-5401; Takei Scientific Instruments Co., Ltd, Tokyo, Japan). Handgrip measurements are performed twice for each hand in an alternating manner, and the highest value is used for analysis

    Measured: Change from study enrollment (day 1) to study completion (day 23; 10 days after the intervention)

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted16 Sep 2025
  2. Study start11 Oct 2025
  3. Primary completion31 Aug 2026 (estimated)
  4. Study completion31 Aug 2026 (estimated)

Resources

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
Parallel groups
Masking
Double blind
Who is masked
Participant, Outcomes assessor
Enrolment
50 participants (estimated)
IDs, dates and publications
ClinicalTrials.gov ID
NCT07175701
Sponsor's protocol ID
KUIRB-2025-0600-05
Other IDs
2025-2
Acronym
ULTRA-CGM
Status last verified
Apr 2026
First submitted
5 Sep 2025
Last updated
17 Apr 2026
Results posted
No
Data monitoring committee
No
FDA-regulated drug
No
FDA-regulated device
No
Individual data sharing
No: To protect personal information, data files containing personally identifiable information will be accessible only to designated researchers, and any external transfer of related data will be strictly prohibited.

Publications

  • Moher D, Schulz KF, Altman DG; CONSORT Group. The CONSORT statement: revised recommendations for improving the quality of reports of parallel-group randomised trials. Clin Oral Investig. 2003 Mar;7(1):2-7. doi: 10.1007/s00784-002-0188-x. Epub 2003 Jan 31.

    PubMed 12673431

  • Imai S, Fukui M, Ozasa N, Ozeki T, Kurokawa M, Komatsu T, Kajiyama S. Eating vegetables before carbohydrates improves postprandial glucose excursions. Diabet Med. 2013 Mar;30(3):370-2. doi: 10.1111/dme.12073. No abstract available.

    PubMed 23167256

  • O'Keefe JH, Bell DS. Postprandial hyperglycemia/hyperlipidemia (postprandial dysmetabolism) is a cardiovascular risk factor. Am J Cardiol. 2007 Sep 1;100(5):899-904. doi: 10.1016/j.amjcard.2007.03.107. Epub 2007 Jun 26.

    PubMed 17719342

  • Borg R, Kuenen JC, Carstensen B, Zheng H, Nathan DM, Heine RJ, Nerup J, Borch-Johnsen K, Witte DR; ADAG Study Group. Real-life glycaemic profiles in non-diabetic individuals with low fasting glucose and normal HbA1c: the A1C-Derived Average Glucose (ADAG) study. Diabetologia. 2010 Aug;53(8):1608-11. doi: 10.1007/s00125-010-1741-9. Epub 2010 Apr 16.

    PubMed 20396998

  • Juvenile Diabetes Research Foundation Continuous Glucose Monitoring Study Group; Fox LA, Beck RW, Xing D. Variation of interstitial glucose measurements assessed by continuous glucose monitors in healthy, nondiabetic individuals. Diabetes Care. 2010 Jun;33(6):1297-9. doi: 10.2337/dc09-1971. Epub 2010 Mar 9.

    PubMed 20215454

  • Shah VN, DuBose SN, Li Z, Beck RW, Peters AL, Weinstock RS, Kruger D, Tansey M, Sparling D, Woerner S, Vendrame F, Bergenstal R, Tamborlane WV, Watson SE, Sherr J. Continuous Glucose Monitoring Profiles in Healthy Nondiabetic Participants: A Multicenter Prospective Study. J Clin Endocrinol Metab. 2019 Oct 1;104(10):4356-4364. doi: 10.1210/jc.2018-02763.

    PubMed 31127824

  • Battelino T, Danne T, Bergenstal RM, Amiel SA, Beck R, Biester T, Bosi E, Buckingham BA, Cefalu WT, Close KL, Cobelli C, Dassau E, DeVries JH, Donaghue KC, Dovc K, Doyle FJ 3rd, Garg S, Grunberger G, Heller S, Heinemann L, Hirsch IB, Hovorka R, Jia W, Kordonouri O, Kovatchev B, Kowalski A, Laffel L, Levine B, Mayorov A, Mathieu C, Murphy HR, Nimri R, Norgaard K, Parkin CG, Renard E, Rodbard D, Saboo B, Schatz D, Stoner K, Urakami T, Weinzimer SA, Phillip M. Clinical Targets for Continuous Glucose Monitoring Data Interpretation: Recommendations From the International Consensus on Time in Range. Diabetes Care. 2019 Aug;42(8):1593-1603. doi: 10.2337/dci19-0028. Epub 2019 Jun 8.

    PubMed 31177185

  • Song J, Oh TJ, Song Y. Individual Postprandial Glycemic Responses to Meal Types by Different Carbohydrate Levels and Their Associations with Glycemic Variability Using Continuous Glucose Monitoring. Nutrients. 2023 Aug 13;15(16):3571. doi: 10.3390/nu15163571.

    PubMed 37630761

  • Mendoza K, Smith-Warner SA, Rossato SL, Khandpur N, Manson JE, Qi L, Rimm EB, Mukamal KJ, Willett WC, Wang M, Hu FB, Mattei J, Sun Q. Ultra-processed foods and cardiovascular disease: analysis of three large US prospective cohorts and a systematic review and meta-analysis of prospective cohort studies. Lancet Reg Health Am. 2024 Sep 2;37:100859. doi: 10.1016/j.lana.2024.100859. eCollection 2024 Sep.

    PubMed 39286398

  • Wang M, Du X, Huang W, Xu Y. Ultra-processed Foods Consumption Increases the Risk of Hypertension in Adults: A Systematic Review and Meta-analysis. Am J Hypertens. 2022 Oct 3;35(10):892-901. doi: 10.1093/ajh/hpac069.

    PubMed 35750049

  • Chen LK, Woo J, Assantachai P, Auyeung TW, Chou MY, Iijima K, Jang HC, Kang L, Kim M, Kim S, Kojima T, Kuzuya M, Lee JSW, Lee SY, Lee WJ, Lee Y, Liang CK, Lim JY, Lim WS, Peng LN, Sugimoto K, Tanaka T, Won CW, Yamada M, Zhang T, Akishita M, Arai H. Asian Working Group for Sarcopenia: 2019 Consensus Update on Sarcopenia Diagnosis and Treatment. J Am Med Dir Assoc. 2020 Mar;21(3):300-307.e2. doi: 10.1016/j.jamda.2019.12.012. Epub 2020 Feb 4.

    PubMed 32033882

  • Kim DW, Song S, Lee JE, Oh K, Shim J, Kweon S, Paik HY, Joung H. Reproducibility and validity of an FFQ developed for the Korea National Health and Nutrition Examination Survey (KNHANES). Public Health Nutr. 2015 Jun;18(8):1369-77. doi: 10.1017/S1368980014001712. Epub 2014 Aug 28.

    PubMed 25167205

  • Jung S, Park S, Kim JY. Comparison of dietary share of ultra-processed foods assessed with a FFQ against a 24-h dietary recall in adults: results from KNHANES 2016. Public Health Nutr. 2022 May;25(5):1166-1175. doi: 10.1017/S1368980022000179. Epub 2022 Jan 19.

    PubMed 35042567

  • Chan AW, Boutron I, Hopewell S, Moher D, Schulz KF, Collins GS, Tunn R, Aggarwal R, Berkwits M, Berlin JA, Bhandari N, Butcher NJ, Campbell MK, Chidebe RCW, Elbourne DR, Farmer AJ, Fergusson DA, Golub RM, Goodman SN, Hoffmann TC, Ioannidis JPA, Kahan BC, Knowles RL, Lamb SE, Lewis S, Loder E, Offringa M, Ravaud P, Richards DP, Rockhold FW, Schriger DL, Siegfried NL, Staniszewska S, Taylor RS, Thabane L, Torgerson DJ, Vohra S, White IR, Hrobjartsson A. SPIRIT 2025 statement: Updated guideline for protocols of randomised trials. PLoS Med. 2025 Apr 28;22(4):e1004589. doi: 10.1371/journal.pmed.1004589. eCollection 2025 Apr.

    PubMed 40294521

  • Danne T, Nimri R, Battelino T, Bergenstal RM, Close KL, DeVries JH, Garg S, Heinemann L, Hirsch I, Amiel SA, Beck R, Bosi E, Buckingham B, Cobelli C, Dassau E, Doyle FJ 3rd, Heller S, Hovorka R, Jia W, Jones T, Kordonouri O, Kovatchev B, Kowalski A, Laffel L, Maahs D, Murphy HR, Norgaard K, Parkin CG, Renard E, Saboo B, Scharf M, Tamborlane WV, Weinzimer SA, Phillip M. International Consensus on Use of Continuous Glucose Monitoring. Diabetes Care. 2017 Dec;40(12):1631-1640. doi: 10.2337/dc17-1600.

    PubMed 29162583

Questions about this trial

What is this clinical trial studying?

A study testing 40-minute one-on-one dietary counseling and nutrition education aimed at reducing ultra-processed food consumption and Standard dietary counseling and nutrition education based on national guidelines in people with Postprandial Glucose and Glucose Levels, run by Korea University at 1 site in South Korea.

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 8 inclusion and 2 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: looking for participants now, as of the sponsor's last update on 17 Apr 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 South Korea. 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?

Contact Yujin Kim, BSN (+82-10-8712-9763, iamyujin@korea.ac.kr), or a site near the patient. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Change in postprandial glucose responses (time frame: Change in mean values from the baseline monitoring period (10-day period before the intervention) to the post-intervention monitoring period (10-day period immediately following the intervention)). It is what the study was designed to measure, not a finding.

Where can I read the original study information?

On the ClinicalTrials.gov record for NCT07175701, which also lists 40 linked publications.

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 17 Apr 2026.

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