NCT03944616

Brief Summary

Diet beverages sweetened with artificial sweeteners occupy a unique category in the food environment as they are a source of intensely sweet taste with no calories. Diet beverages are the single largest contributor to artificial sweetener intake in the U.S. diet, and people with diabetes are the highest consumers of diet beverages, tending to consume them as a replacement for dietary sources of sugar, especially in place of sugar-sweetened beverages. This behavior has been endorsed by dietetic and scientific organizations, and diet beverages are marketed as being synonymous with better health, suitable for weight loss, and thus advantageous for diabetes control. The underlying public health concern is that there are few data to support or refute the benefit or harm of habitual diet beverage consumption by people with diabetes; therefore randomized trials with relevant outcomes must be conducted because they would address many limitations of previous research and have major implications for dietary recommendations on diet beverage intake and primary and secondary prevention of chronic disease. To begin addressing this important scientific gap the investigators are testing the effect of diet beverage intake on diabetes control parameters in free-living adults with type 2 diabetes in a randomized, two arm parallel trial with a run-in period of 2-weeks and an active intervention period of 24-weeks. This study will recruit 200 patients with type 2 diabetes who are usual consumers of commercial diet beverages and randomize them to receive and consume either: 1) A commercial diet beverage of choice (3 servings or 24 oz. daily); or 2) Unflavored bottled water of choice (sparkling or plain) (3 servings or 24 oz. daily). The primary outcome will be a central measure of clinical diabetes control in glycated hemoglobin (HbA1c). The study will also measure the nature and magnitude of glycemic excursions via continuous glucose monitors, as well as clinical markers of cardiometabolic risk and kidney function. Lastly, investigators will measure plausible mechanisms whereby diet beverage intake may alter risk by assessing the effect of diet beverage intake on the functional composition of the gut microbiome via stool samples and comprehensive metabolomics, satiety hormones, as well as usual dietary intake, and upstream behavioral pathways which may inform dietary intake patterns.

Trial Health

87
On Track

Trial Health Score

Automated assessment based on enrollment pace, timeline, and geographic reach

Enrollment
181

participants targeted

Target at P75+ for not_applicable type-2-diabetes

Timeline
Completed

Started Jun 2019

Longer than P75 for not_applicable type-2-diabetes

Geographic Reach
1 country

2 active sites

Status
completed

Health score is calculated from publicly available data and should be used for screening purposes only.

Trial Relationships

Click on a node to explore related trials.

Study Timeline

Key milestones and dates

First Submitted

Initial submission to the registry

November 19, 2018

Completed
6 months until next milestone

First Posted

Study publicly available on registry

May 9, 2019

Completed
28 days until next milestone

Study Start

First participant enrolled

June 6, 2019

Completed
4.8 years until next milestone

Primary Completion

Last participant's last visit for primary outcome

March 21, 2024

Completed
Same day until next milestone

Study Completion

Last participant's last visit for all outcomes

March 21, 2024

Completed
1.5 years until next milestone

Results Posted

Study results publicly available

September 11, 2025

Completed
Last Updated

September 11, 2025

Status Verified

September 1, 2025

Enrollment Period

4.8 years

First QC Date

November 19, 2018

Results QC Date

May 13, 2025

Last Update Submit

September 9, 2025

Conditions

Keywords

Diet beveragesdietdiabetes controlartificial sweetenerscontinuous glucose monitorgut microbiomemetabolomics

Outcome Measures

Primary Outcomes (1)

  • HbA1c

    Glycated hemoglobin

    Time 0 (directly after 2-week run-in), 12, 24 weeks

Secondary Outcomes (25)

  • Time In Range

    All 14 day periods: Run-in (2-weeks, usual-baseline), weeks 11 and 12 (14 days), weeks 23 and 24 (14 days)

  • Glycemic Variability

    All 14 day periods: Run-in (2-weeks, usual-baseline), weeks 11 and 12 (14 days), weeks 23 and 24 (14 days)

  • Mean Glucose (mg/dl)

    All 14 day periods: Run-in (2-weeks, usual-baseline), weeks 11 and 12 (14 days), weeks 23 and 24 (14 days)

  • Fasting Glucose

    Time 0 (directly after 2-week run-in), 12, 24 weeks

  • Fasting Insulin (Pmol/L)

    Time 0 (directly after 2-week run-in), week 12, week 24

  • +20 more secondary outcomes

Study Arms (2)

Diet Beverage

ACTIVE COMPARATOR

Participants will receive and consume three daily servings (24 ounces) of a non-caloric commercial diet beverage of their choice sweetened with FDA approved artificial sweeteners.

Behavioral: Diet Beverage

Water

EXPERIMENTAL

Participants will receive and consume three daily servings (24 ounces) of plain bottled/canned water in place of their usual commercial diet beverage. The water will be unflavored, unsweetened, non-caloric, and may be plain or sparkling. Participants randomized to consume water will be instructed to avoid intake of diet beverages.

Behavioral: Water

Interventions

Diet BeverageBEHAVIORAL

Participants will receive and consume three daily servings (24 ounces) of a non-caloric commercial diet beverage of their choice sweetened with FDA approved artificial sweeteners.

Diet Beverage
WaterBEHAVIORAL

Participants will receive and consume three daily servings (24 ounces) of plain bottled/canned water in place of their usual commercial diet beverage. The water will be unflavored, unsweetened, non-caloric, and may be plain or sparkling. Participants randomized to consume water will be instructed to avoid intake of diet beverages.

Water

Eligibility Criteria

Age35 Years+
Sexall
Healthy VolunteersNo
Age GroupsAdult (18-64), Older Adult (65+)

You may qualify if:

  • Physician diagnosed type 2 diabetes ≥ 6 months prior to screening
  • HbA1c 6.5-8.5% at participant screening
  • Current treatment with lifestyle changes or stable diabetes-related medication levels for the past 3 months
  • Willingness to provide consent to contact treating physician and physician agreement to refrain from changing diabetes-related medications during the trial (change defined as \> 2 fold change in dose of any 1 hyperglycemic agent or addition or subtraction of an agent)
  • No physician-directed medication change for 3 months if prescribed medication for lipids or blood pressure
  • Usual consumers of diet beverages (≥ 3 servings/ week (24 oz.) and the willingness to maintain fidelity of the intervention, and participate in all aspects of the intervention
  • Not actively looking to make major lifestyle alterations during the study period with stable weight for 2 months (within 3%).

You may not qualify if:

  • Type 1 diabetes or suspected type 1 diabetes (lean with polyuria, polydipsia, and weight loss with little response to metformin)
  • "Secondary" diabetes due to specific causes (e.g. monogenic syndromes, pancreatic surgery, and pancreatitis)
  • Diabetic Ketoacidosis hospitalization within last 6 months
  • Severe/major hypoglycemia in the last 3 months-severe/major hypoglycemia is defined as a hypoglycemic event in which patient requires assistance of another person to manage the episode
  • Glucocorticoid use (prednisone 2.5 mg/d or more or its equivalent)
  • History of intolerance or allergy to diet beverages or AS or phenylketonuria
  • Any condition that is known to affect the validity of the glycemic measures (Hba1c)
  • Major cardiovascular disease event or surgery within past 6 months
  • Gastrointestinal disease
  • Renal or liver disease
  • Current treatment for cancer
  • Those with major surgery planned or history of bariatric surgery
  • Antibiotic treatment (\> 6 days) within past 6 months
  • Currently pregnant (via self-report) or planning to become pregnant during study period; \<1 year postpartum and breast feeding
  • Current participation in another interventional clinical trial
  • +5 more criteria

Contact the study team to confirm eligibility.

Sponsors & Collaborators

Study Sites (2)

University of California, Irvine

Irvine, California, 92697, United States

Location

University of Minnesota

Minneapolis, Minnesota, 55454, United States

Location

MeSH Terms

Conditions

Diabetes Mellitus, Type 2

Interventions

Artificially Sweetened BeveragesWater

Condition Hierarchy (Ancestors)

Diabetes MellitusGlucose Metabolism DisordersMetabolic DiseasesNutritional and Metabolic DiseasesEndocrine System Diseases

Intervention Hierarchy (Ancestors)

BeveragesDiet, Food, and NutritionPhysiological PhenomenaFood and BeveragesHydroxidesAlkaliesInorganic ChemicalsAnionsIonsElectrolytesOxidesOxygen Compounds

Results Point of Contact

Title
Dr. Andrew Odegaard
Organization
University of California, Irvine

Publication Agreements

PI is Sponsor Employee
No
Restrictive Agreement
No

Study Design

Study Type
interventional
Phase
not applicable
Allocation
RANDOMIZED
Masking
SINGLE
Who Masked
OUTCOMES ASSESSOR
Masking Details
All nursing staff/phlebotomist collecting physical samples, and the lab analyzing the samples will be masked to the trial arm the participant is in. The biostatistician performing the final analyses will also be masked.
Purpose
PREVENTION
Intervention Model
PARALLEL
Model Details: This study is testing the effect of commercial diet beverage intake on diabetes control parameters in free-living adults with type 2 diabetes in a randomized, two arm parallel trial with a run-in period of 2-weeks and an active intervention period of 24-weeks. We will recruit 200 patients with type 2 diabetes who are usual consumers of commercial diet beverages and randomize them to receive and consume either: 1) A commercial diet beverage of choice (3 servings or 24 oz. daily); or 2) Unflavored bottled water of choice (sparkling or plain) (3 servings or 24 oz. daily).
Sponsor Type
OTHER
Responsible Party
PRINCIPAL INVESTIGATOR
PI Title
Associate Professor

Study Record Dates

First Submitted

November 19, 2018

First Posted

May 9, 2019

Study Start

June 6, 2019

Primary Completion

March 21, 2024

Study Completion

March 21, 2024

Last Updated

September 11, 2025

Results First Posted

September 11, 2025

Record last verified: 2025-09

Data Sharing

IPD Sharing
Will not share

It is not yet known if there will be a plan to make IPD available.

Locations