The Breakfast Study

August 27, 2026 updated by: Laura Saslow, University of Michigan

The Breakfast Study: A Small Steps, Low-literacy, Breakfast-focused Dietary Self-management Intervention for Adults With Poorly Controlled Type 2 Diabetes

The investigators conducted an acceptability, feasibility, preliminary effectiveness trial of a 4-month, online, very low-carbohydrate breakfast-focused program in 120 adults with type 2 diabetes. The investigators measured acceptability and feasibility, plus critical efficacy outcomes, such as changes in HbA1c, anti-hyperglycemic medications, glycemic variability, body weight, blood pressure, and lipids.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Completed

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Detailed Description

More than 15% of U.S. adults with type 2 diabetes have poorly controlled blood gluocse, here defined as a glycated hemoglobin (HbA1c) level of 7.0% or higher. These adults have an elevated health risk of a variety of outcomes, including amputation and mortality from cardiovascular disease and from all causes. Nutrition- focused interventions can be effective for improving glycemic control, reducing anti-hyperglycemic medications, and reducing body weight, all of which are critical outcomes for adults with type 2 diabetes. However, typical nutrition-focused interventions can be burdensome, often requiring complex instructions and a complete overhaul of one's diet. Additionally, adults with poorly controlled type 2 diabetes are more likely to have low literacy levels, which can be a barrier for adherence to complex interventions. Therefore, an effective intervention for adults with poorly controlled diabetes who may have lower health literacy levels is necessary to reduce both HbA1c levels and anti-hyperglycemic medications. Carbohydrate intake has the strongest impact on post-prandial glycemia of any dietary factor, and a very low-carbohydrate diet-due to its ability to improve glycemic control-is now recommended by the American Diabetes Association (ADA) for the treatment of type 2 diabetes. The investigators hypothesized that some of the benefits of a very low-carbohydrate diet may be available to individuals who change only their breakfasts to be very low-carbohydrate, rather than modifying their entire diet.

Thus, the investigators conducted an acceptability, feasibility, preliminary effectiveness trial of a 4-month, online, small- steps, low-literacy, very low-carbohydrate breakfast-focused program in 120 adults with poorly controlled type 2 diabetes. The investigators measured acceptability and feasibility, plus critical efficacy outcomes, such as changes in HbA1c, anti-hyperglycemic medications, glycemic variability, body weight, blood pressure, and lipids.

The investigators also tested whether factors such as sex, health literacy level, and baseline insulin resistance significantly moderate the impact of the intervention on change in HbA1c and change in anti-hyperglycemic medications.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Actual)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
119

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • 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 Locations

  • United States
    • Michigan
      • Ann Arbor, Michigan, United States, 48109
        • University of Michigan

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

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • HbA1c 7% or higher
  • 18-80 years old
  • The ability to understand verbal and written English
  • Willingness to follow the prescribed diet
  • Able to consent and follow directions
  • Willingness to regularly check blood glucose levels as required

Exclusion Criteria:

  • Inability to provide informed consent
  • Pregnant, breastfeeding, or planning for either in the next 6 months or <6 months postpartum
  • Low C-peptide and possible subsequent GAD 65 level that suggests type 1 diabetes, clinical factors that suggest type 1 diabetes (lean, lack of family history, and diabetic ketoacidosis in the past) or a previous diagnosis of type 1 diabetes or latent autoimmune diabetes
  • Triglycerides are greater than 999mg/dL on the screening blood draw
  • Cancer, heart failure, or kidney failure
  • Vegan
  • Untreated mental health condition
  • Currently following a very low-carbohydrate diet or breakfasts
  • Thyroid levels out of range
  • Alcoholism
  • Previous bariatric surgery
  • Difficulty chewing or swallowing
  • Dependence on others for food preparation
  • Currently enrolled in another investigative study that might conflict with this research

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: Treatment
  • Allocation: N/A
  • Interventional Model: Single Group Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Experimental: Very low-carbohydrate breakfast
Materials encouraged eating a very low-carbohydrate breakfast (or first meal of the day), with no more than about 5-10 non-fiber (net) grams of carbohydrates each.
Behavioral: Breakfast
Participant were provided recipes and information to support this dietary change.

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Intervention satisfaction
Time Frame: At 4 months
A 1-item measure about intervention satisfaction. We asked participants, "How would you rate your overall satisfaction with the program?" The item was rated from 1 = very dissatisfied to 6 = very satisfied, with higher scores reflecting greater satisfaction.
At 4 months

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Weekly dietary adherence
Time Frame: Weekly over 4 months
A 1-item measure about dietary adherence. We asked participants to reflect on the past week and rate whether they ate a low-carbohydrate breakfast. The item was rated from 1 = not at all to 7 = very much so, with higher scores reflecting greater adherence. Dietary adherence was collected weekly over the 4-month intervention. Average adherence across the intervention was reported.
Weekly over 4 months
Change in PROMIS Sleep Disturbance T-score
Time Frame: Baseline, 4 months
The 4-item PROMIS sleep disturbance subscale measures the extent to which patients experience problems with sleep over the past 7 days using a 5-point Likert scale. The subscale is measured using T-scores (mean 50, SD 10), with higher scores reflecting more severe sleep problems. To assess the effect of dietary change on sleep disturbance, the change in PROMIS sleep disturbance T-scores from baseline to 4 months was evaluated.
Baseline, 4 months
Change in PROMIS Pain Interference T-score
Time Frame: Baseline, 4 months
The 4-item PROMIS subscale for pain interference measures the extent to which patients experience problems with pain interference over the past 7 days using a 5-point Likert scale. The subscale is measured using T-scores (mean 50, SD 10), with higher scores reflecting greater pain interference. To assess the effects of dietary changes on pain, the change in PROMIS sleep T-scores from baseline to 4 months was evaluated.
Baseline, 4 months
Change in PROMIS Anxiety T-score
Time Frame: Baseline, 4 months
The 4-item PROMIS subscale for depression measures the extent to which patients experience depressive symptoms over the past 7 days using a 5-point Likert scale. The subscale is measured using T-scores (mean 50, SD 10), with higher scores reflecting greater depression. To assess the effects of dietary changes on depression, the change in PROMIS depression T-scores from baseline to 4 months was evaluated.
Baseline, 4 months
Change in PROMIS Depression T-score
Time Frame: Baseline, 4 months
The 4-item PROMIS subscale for depression measures the extent to which patients experience depressive symptoms over the past 7 days using a 5-point Likert scale. The subscale is measured using T-scores (mean 50, SD 10), with higher scores reflecting greater depression. To assess the effects of dietary changes on depression, the change in PROMIS depression T-scores from baseline to 4 months was evaluated.
Baseline, 4 months
Change in PROMIS Fatigue T-score
Time Frame: Baseline, 4 months
The 4-item PROMIS subscale for fatigue measures the extent to which patients experience problems with fatigue over the past 7 days using a 5-point Likert scale. The subscale is measured using T-scores (mean 50, SD 10), with higher scores reflecting greater fatigue. To assess the effects of dietary changes on fatigue, the change in PROMIS fatigue T-scores from baseline to 4 months was evaluated.
Baseline, 4 months
Change in PROMIS Physical Function T-score
Time Frame: Baseline, 4 months
The 4-item PROMIS subscale for physical function measures the extent to which patients experience problems with physical function over the past 7 days using a 5-point Likert scale. The subscale is measured using T-scores (mean 50, SD 10), with higher scores reflecting better physical function. To assess the effects of dietary changes on physical function, the change in PROMIS physical function T-scores from baseline to 4 months was evaluated.
Baseline, 4 months
Change in PROMIS Social Roles T-score
Time Frame: Baseline, 4 months
The 4-item PROMIS subscale for social roles measures the extent to which patients experience problems with their social roles over the past 7 days using a 5-point Likert scale. The subscale is measured using T-scores (mean 50, SD 10), with higher scores reflecting better social roles. To assess the effects of dietary changes on social roles, the change in PROMIS social roles T-scores from baseline to 4 months was evaluated.
Baseline, 4 months
Change in PROMIS Pain Intensity
Time Frame: Baseline, 4 months
The 1-item PROMIS subscale for pain intensity measures average pain intensity over the past 7 days using a 10-point Likert scale, with higher scores reflecting greater pain. To assess the effects of dietary changes on pain intensity, the change in PROMIS pain intensity T-scores from baseline to 4 months was evaluated.
Baseline, 4 months
Change in HbA1c
Time Frame: Baseline, 4 months
HbA1c is the proportion of hemoglobin in the blood that has glucose attached to it relative to total hemoglobin. It reflects average blood glucose levels over approximately the previous 2-3 months. To assess the effect of dietary change on HbA1c, the change in HbA1c from baseline to 4 months were evaluated. A negative change indicates an improvement in HbA1c from baseline.
Baseline, 4 months
Change in anti-hyperglycemic medications
Time Frame: Baseline, 4 months
The Medication Effect Score (MES) quantifies the overall intensity of antiglycemic therapy based on potency and dosages of medications (Alexopoulos et al., 2021), with higher scores indicating greater medication intensity. It is interpreted as the reduction in HbA1c attributable to the medication regime. For each diabetes medication, the percentage of the maximum recommended daily dose is multiplied by an adjustment factor reflecting its expected hemoglobin A1c-lowering potency; these values are summed to yield the total MES. Scores range from 0 upward (no fixed maximum), with lower scores reflecting lower medication intensity. The change in MES from baseline to 4 months was evaluated, with negative values indicating a reduction in medication intensity.
Baseline, 4 months

Collaborators and Investigators

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

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
University of Michigan

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

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)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
August 2, 2023

Primary Completion (Actual)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
October 9, 2025

Study Completion (Actual)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
October 17, 2025

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
July 17, 2023

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
August 2, 2023

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
August 14, 2023

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
September 1, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
August 27, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
November 1, 2025

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • HUM00225646

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

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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