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RecruitingNCT07223151SPARKLEUpdated Aug 6, 2026

A Sensory Strategy to Cut Sugary Beverages in African/American and Latine Adolescents

An interventional study of Unsweetened Sparkling Water Replacement and Progressively Reduced Sugar Beverage Replacement in Obesity, Adolescent, Dietary Sugars and Taste Perception, sponsored by Nana Gletsu Miller. Recruiting at 3 sites in United States. Open to participants aged 12 Years to 18 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2026-08-06.

Sponsored by Nana Gletsu Miller · Not applicable, Interventional, and Prevention

Phase
Not applicable
Study type
Interventional
Enrollment
63
Allocation
Randomized
Ages
12 Years to 18 Years
Sex
All
01

Study summary

The goal of this clinical trial is to test whether replacing sugary sodas with unsweetened, flavored sparkling waters can reduce added sugar intake and improve health in Black/African American and Latine adolescents with obesity who prefer sweet-tasting beverages. The main questions it aims to answer are:

  • Does replacing sugary sodas with water change liking for sugary drinks, and water?
  • Do shifts in liking for sweetness lead to improved diet quality and cardiometabolic health?

Researchers will compare replacing sugary sodas with one of three alternative beverages: unsweetened sparkling water, plain water, and beverages with gradually reduced sugar to determine which strategy is most effective.

Participants will:

  • Replace sugary sodas with study drinks for 4 weeks
  • Complete taste tests to measure their liking for and sensory experience of sweetness over 8-weeks
  • Provide dietary recalls, body measurements, and blood samples over 8-weeks
Read the detailed description

This randomized controlled trial aims to evaluate the effects of replacing sugar-sweetened sodas with unsweetened, flavored sparkling waters, progressively sugar-reduced sodas, or plain water in adolescents who are classified as "sweet-likers"-individuals who prefer higher concentrations of sugar in beverages. The study focuses on a high-risk group: adolescents ages 12-18 who self-identify as Black/African American or Latine and have obesity (BMI >95th percentile).

63 adolescents who are classified as sweet-likers and meet additional inclusion criteria will be enrolled in a randomized 3-arm intervention for 4 weeks, with an additional 4-week follow-up period. Participants will be randomized into one of the following groups:

USW (Unsweetened Sparkling Water): Replaces sodas with flavored, unsweetened carbonated water.

PRS (Progressively Reduced Sugar): Replaces sodas with carbonated beverages with decreasing sugar concentrations, ending with unsweetened carbonated water.

PW (Plain Water - Control): Replaces sodas with still, plain water.

Participants will replace all typical sugary sodas with study beverages during the 4-week intervention. Study assessments include sensory testing for liking, sweetness intensity, and "just about right" level of sweetness in sparkling and plain water at baseline, week 2, week 4, and week 8. Additionally, dietary intake (via 24-hour dietary recalls), anthropometrics (height, weight, waist circumference), blood pressure, and blood biomarkers (fasting glucose, insulin, triglycerides) will be measured at baseline, week 4, and week 8.

The primary hypothesis is that exposure to unsweetened beverages (especially in the USW and PRS groups) will reduce participants' liking for higher concentrations of sugar in beverages and increasing liking for lower concentrations of sugar in beverages. It is also hypothesized that these changes may correspond with improvements in cardiometabolic markers, particularly serum triglycerides. Insulin resistance (HOMA-IR), blood pressure, and body weight will also be measured but are less likely to shift in the relatively short time period (8 weeks).

This trial addresses the persistent challenge of high SSB consumption in racial and ethnic minority adolescents-a group that faces disproportionate risk of obesity, prediabetes, and cardiometabolic disease. By integrating sensory science with behavior change, this intervention seeks to develop more effective strategies to support reduced sugar intake in adolescents who have strong preferences for sweetness.

02

Conditions studied

  • Obesity, Adolescent
  • Dietary Sugars
  • Taste Perception
  • Insulin Resistance
  • Feeding Behavior

Keywords

  • Obesity
  • Adolescent
  • Sugar-Sweetened Beverages
  • Taste Perception
  • Insulin Resistance
  • Sweet Taste Preference
  • Latine Youth
  • African American Youth
  • Dietary Intervention
  • Beverage Replacement
  • Sugar Reduction
  • Sensory Evaluation
  • Randomized Controlled Trial
03

Who can participate

Ages eligible
12 Years to 18 Years
Sexes eligible
All
Accepts healthy volunteers
Yes

Inclusion criteria

  • Adolescents ages 12 to 18 who display a "sweet-liker" pattern, characterized by a preference for higher concentrations of sugar in beverages, specifically identifying 0.3M (10.3% sucrose) or above as their most liked sample.
  • Adolescents consumes sugar-sweetened soda greater than or equal to 2 times per week. Adolescents must also indicate a willingness to drink study beverages; not currently dieting/changing diet.

Exclusion criteria

Exclusion Criteria:

  • Adolescent participant is pregnant, since pregnancy affects taste perception
  • Participant is allergic or intolerant to the items we are testing.
  • Adolescent with type 1 or type 2 diabetes (self-declared or detected at screening visit through fasting glucose)
  • Use of GLP-1 receptor agonists intended for weight loss.
04

Study design

Phase
Not applicable
Primary purpose
Prevention
Allocation
Randomized
Intervention model
Parallel assignment
Masking
None (open label)
Enrollment
63 participants (estimated)

Study arms

  • Experimental
    Unsweetened Sparkling Water (USW)

    Participants in this group will replace all sugar-sweetened sodas with flavored, unsweetened sparkling waters for 4 weeks.

    Behavioral: Unsweetened Sparkling Water Replacement

  • Experimental
    Progressively Reduced Sugar (PRS)

    Participants in this group will replace sugar-sweetened sodas with carbonated beverages that contain decreasing levels of sugar each week over a 4-week period, ending with a fully unsweetened sparkling water.

    Behavioral: Progressively Reduced Sugar Beverage Replacement

  • Active comparator
    Plain Water (PW)

    Participants in this group will replace all sugar-sweetened sodas with plain, still water for 4 weeks. This arm serves as a control to compare outcomes against both the unsweetened sparkling water and gradually reduced sugar beverage interventions.

    Behavioral: Plain Water Replacement

Interventions

  • BehavioralUnsweetened Sparkling Water Replacement

    Participants replace all sugar-sweetened sodas with flavored, unsweetened sparkling waters for 4 weeks.

  • BehavioralProgressively Reduced Sugar Beverage Replacement

    Participants replace sugary sodas with beverages containing gradually decreasing sugar concentrations (weekly), ending with unsweetened sparkling water.

  • BehavioralPlain Water Replacement

    Participants replace all sugar-sweetened sodas with plain, still water for 4 weeks. This serves as a comparator to evaluate sensory and metabolic changes.

05

What researchers measure

Primary outcomes

  1. Liking ratings changes for sugar concentrations over time

    Our primary outcome is the interaction of time with liking for different sugar concentrations. We expect to observe a significant Time\*Sugar Concentration interaction effect for these liking ratings. We expect the interaction term to show that higher concentrations of sugar had lower liking ratings by weeks 4 and 8 (compared to baseline), but that lower concentrations of sugar had higher liking ratings by weeks 4 and 8. Liking ratings are collected on a scale from -110 to 110, with internal markings at -100 Worst ever, -50 Dislike, 0 Neutral, 50 Like, 100 Best ever.

    Time frame: Baseline, Week 2, Week 4, Week 8

Secondary outcomes

  1. Diet quality changes over time

    We will use the ASA24 method to gather data on food intake. We will apply the Healthy Eating Index method to calculate diet quality. We expect to see improvements in diet quality at weeks 4 and 8 compared to baseline.

    Time frame: Baseline, Week 4, Week 8

  2. Serum triglyceride changes over time

    A secondary outcome is the main effect of time on serum triglycerides. We expect to observe significant decreases in serum triglycerides at weeks 4 and 8 compared to baseline.

    Time frame: Baseline, Week 4, Week 8

  3. Change in fasting glucose over time

    We will also evaluate fasting glucose by serum analysis.

    Time frame: Baseline, Week 4, Week 8

  4. Change in insulin resistance over time

    We will also evaluate insulin resistance (HOMA-IR), which is a measure of fasting glucose multiplied by fasting insulin.

    Time frame: Baseline, Week 4, Week 8

  5. Change in BMI (body mass index) z-score

    We will also evaluate BMI z-score for changes over time

    Time frame: Baseline, Week 4, Week 8

  6. Beverage Consumption Compliance

    Participants report their beverage consumption and compliance will be assessed.

    Time frame: Baseline, Week 4, Week 8

  7. Change in Systolic Blood Pressure

    Systolic Blood Pressure change over time will be evaluated.

    Time frame: Baseline, Week 4, Week 8

  8. Change in Diastolic Blood Pressure

    Diastolic Blood Pressure change over time will be evaluated.

    Time frame: Baseline, Week 4, Week 8

  9. Change in Waist Circumference

    Waist circumference will be evaluated over time.

    Time frame: Baseline, Week 4, Week 8

  10. Number of Participants experiencing tooth sensitivity or gastrointestinal symptoms

    Time frame: Week 4

06

Study locations

2 of 3 sites recruiting
  • Indiana University School of Public Health - Bloomington
    Bloomington, Indiana 47405, United States
    Not yet recruiting
  • Indiana University Hospital
    Indianapolis, Indiana 46202, United States
    Recruiting
  • Purdue University
    West Lafayette, Indiana 47907, United States
    Recruiting
07

References and documents

Publications

  • Matsuda M, DeFronzo RA. Insulin sensitivity indices obtained from oral glucose tolerance testing: comparison with the euglycemic insulin clamp. Diabetes Care. 1999 Sep;22(9):1462-70. doi: 10.2337/diacare.22.9.1462. PubMed 10480510 ↗
  • Wang J, Light K, Henderson M, O'Loughlin J, Mathieu ME, Paradis G, Gray-Donald K. Consumption of added sugars from liquid but not solid sources predicts impaired glucose homeostasis and insulin resistance among youth at risk of obesity. J Nutr. 2014 Jan;144(1):81-6. doi: 10.3945/jn.113.182519. Epub 2013 Nov 6. PubMed 24198307 ↗
  • Boushey CJ, Kerr DA, Wright J, Lutes KD, Ebert DS, Delp EJ. Use of technology in children's dietary assessment. Eur J Clin Nutr. 2009 Feb;63 Suppl 1(Suppl 1):S50-7. doi: 10.1038/ejcn.2008.65. PubMed 19190645 ↗
  • Bailey RL, Fulgoni VL, Cowan AE, Gaine PC. Sources of Added Sugars in Young Children, Adolescents, and Adults with Low and High Intakes of Added Sugars. Nutrients. 2018 Jan 17;10(1):102. doi: 10.3390/nu10010102. PubMed 29342109 ↗
  • Reedy J, Krebs-Smith SM. Dietary sources of energy, solid fats, and added sugars among children and adolescents in the United States. J Am Diet Assoc. 2010 Oct;110(10):1477-84. doi: 10.1016/j.jada.2010.07.010. PubMed 20869486 ↗
  • Banfield EC, Liu Y, Davis JS, Chang S, Frazier-Wood AC. Poor Adherence to US Dietary Guidelines for Children and Adolescents in the National Health and Nutrition Examination Survey Population. J Acad Nutr Diet. 2016 Jan;116(1):21-27. doi: 10.1016/j.jand.2015.08.010. Epub 2015 Sep 26. PubMed 26391469 ↗
  • Andes LJ, Cheng YJ, Rolka DB, Gregg EW, Imperatore G. Prevalence of Prediabetes Among Adolescents and Young Adults in the United States, 2005-2016. JAMA Pediatr. 2020 Feb 1;174(2):e194498. doi: 10.1001/jamapediatrics.2019.4498. Epub 2020 Feb 3. PubMed 31790544 ↗
  • Valicente V, Gletsu-Miller N, Running CA. Secondary Analysis of Sweetness Liking from Pilot Study Replacing Sugar Sweetened Soda with Flavored, Unsweetened Sparkling Water. J Am Nutr Assoc. 2025 Jan;44(1):1-13. doi: 10.1080/27697061.2024.2369819. Epub 2024 Jul 22. PubMed 39037472 ↗

Individual participant data

Plan to share: No — Individual participant data will not be shared due to the sensitive nature of the data collected from a minor population (adolescents), limited consent for data sharing. Future data sharing may be reconsidered following additional ethical review and participant re-consent where appropriate.

08

Registry details

Key details

Study ID
NCT07223151
Lead sponsor
Nana Gletsu Miller
Collaborators
Purdue University
Responsible party
Nana Gletsu Miller (Associate Professor, Applied Health Science, Indiana University Bloomington, Indiana University) — Sponsor-investigator
First posted
Oct 31, 2025
Start date
Jul 25, 2025
Primary completion
Jun 2027 (estimated)
Completion
Jun 2027 (estimated)
Last update
Aug 6, 2026

Study contacts

Nana Gletsu Miller, PhD
Contact
ngletsum@iu.edu
+1 (812) 855-9110

Oversight

Data monitoring committee
No
FDA-regulated drug
No
FDA-regulated device
No
View the source record on ClinicalTrials.gov ↗

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