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

October 29, 2025 updated by: Nana Gletsu Miller

Trading Sugar for Sparkles in Adolescents, A Sensory Approach for Reducing Added Sugar From Sweetened Beverages

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

Study Overview

Status

Recruiting

Conditions

Intervention / Treatment

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.

Study Type

Interventional

Enrollment (Estimated)

63

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

  • Name: Nana Gletsu Miller, PhD
  • Phone Number: +1 (812) 855-9110
  • Email: ngletsum@iu.edu

Study Locations

  • United States
    • Indiana
      • Bloomington, Indiana, United States, 47405
        • Not yet recruiting
        • Indiana University School of Public Health - Bloomington
        • Contact:
          • Nana Gletsu Miller, PhD
          • Phone Number: 812-855-9110
          • Email: ngletsum@iu.edu
      • Indianapolis, Indiana, United States, 46202
        • Recruiting
        • Indiana University Hospital
        • Contact:
          • Nana Gletsu Miller, PhD
          • Phone Number: 812-855-7643
          • Email: ngletsum@iu.edu
      • West Lafayette, Indiana, United States, 47907
        • Recruiting
        • Purdue University
        • Contact:

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Child
  • Adult

Accepts Healthy Volunteers

Yes

Description

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.
  • Have obesity (body mass index [BMI] > 95%). During screening, subjects' height and weight will be measured to calculate BMI, and BMI will be balanced across study arms using stratified randomization.
  • Adolescents must also indicate a willingness to drink study beverages; not currently dieting/changing diet.

Exclusion Criteria:

  • For the primary objective. Exclusion Criteria:

    • Adolescent participant is pregnant, since pregnancy affects taste perception
    • Participant is allergic or intolerant to the items we are testing.

For the secondary objective. Exclusion Criteria:

  • Adolescent with type 1 or type 2 diabetes (self-declared or detected at screening visit through fasting glucose)
  • Currently consume unsweetened, sparkling water two or more times per week.
  • Adolescent participant is pregnant, since pregnancy affects taste perception
  • Participant is allergic or intolerant to the items we are testing.
  • Allergic or intolerant to the items that we are testing.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Prevention
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
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
Participants replace all sugar-sweetened sodas with flavored, unsweetened sparkling waters for 4 weeks.
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
Participants replace sugary sodas with beverages containing gradually decreasing sugar concentrations (weekly), ending with unsweetened sparkling water.
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
Participants replace all sugar-sweetened sodas with plain, still water for 4 weeks. This serves as a comparator to evaluate sensory and metabolic changes.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Liking ratings changes for sugar concentrations over time
Time Frame: Baseline, Week 2, Week 4, Week 8

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.
Baseline, Week 2, Week 4, Week 8

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Diet quality changes over time
Time Frame: Baseline, Week 4, Week 8
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.
Baseline, Week 4, Week 8
Serum triglyceride changes over time
Time Frame: Baseline, Week 4, Week 8
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.
Baseline, Week 4, Week 8
Change in fasting glucose over time
Time Frame: Baseline, Week 4, Week 8
We will also evaluate fasting glucose by serum analysis.
Baseline, Week 4, Week 8
Change in insulin resistance over time
Time Frame: Baseline, Week 4, Week 8
We will also evaluate insulin resistance (HOMA-IR), which is a measure of fasting glucose multiplied by fasting insulin.
Baseline, Week 4, Week 8
Change in BMI (body mass index) z-score
Time Frame: Baseline, Week 4, Week 8
We will also evaluate BMI z-score for changes over time
Baseline, Week 4, Week 8
Beverage Consumption Compliance
Time Frame: Baseline, Week 4, Week 8
Participants report their beverage consumption and compliance will be assessed.
Baseline, Week 4, Week 8
Change in Systolic Blood Pressure
Time Frame: Baseline, Week 4, Week 8
Systolic Blood Pressure change over time will be evaluated.
Baseline, Week 4, Week 8
Change in Diastolic Blood Pressure
Time Frame: Baseline, Week 4, Week 8
Diastolic Blood Pressure change over time will be evaluated.
Baseline, Week 4, Week 8
Change in Waist Circumference
Time Frame: Baseline, Week 4, Week 8
Waist circumference will be evaluated over time.
Baseline, Week 4, Week 8
Number of Participants experiencing tooth sensitivity or gastrointestinal symptoms
Time Frame: Week 4
Week 4

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Nana Gletsu Miller

Collaborators

Purdue University

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Helpful Links

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

July 25, 2025

Primary Completion (Estimated)

June 1, 2027

Study Completion (Estimated)

June 1, 2027

Study Registration Dates

First Submitted

July 30, 2025

First Submitted That Met QC Criteria

October 29, 2025

First Posted (Estimated)

October 31, 2025

Study Record Updates

Last Update Posted (Estimated)

October 31, 2025

Last Update Submitted That Met QC Criteria

October 29, 2025

Last Verified

October 1, 2025

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • IRB#25860 (Other Identifier: Heartland Children's Nutrition Collaborative, supported by Riley Children's Foundation)

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

IPD Plan Description

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.

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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