Very Low–Carbohydrate Breakfast Intervention for Adults with Type 2 Diabetes and Persistent Hyperglycemia: Protocol for a Digital, Nonrandomized Pre-Post Study

TL;DR

This study tests a digital, low-carb breakfast intervention for adults with type 2 diabetes and high blood sugar to see if it improves health outcomes.

Contribution

It introduces a targeted, accessible, and simplified dietary intervention focusing only on breakfast for managing type 2 diabetes.

Findings

The study will assess acceptability, feasibility, and preliminary effectiveness of a low-carb breakfast intervention.

It will measure changes in HbA1c, medication use, and other health markers in participants.

Results may support future research on lowering barriers to dietary interventions for diabetes.

Abstract

More than 15% of US adults with type 2 diabetes have persistent hyperglycemia. Adults with persistent hyperglycemia and type 2 diabetes 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 antihyperglycemic medications, and reducing body weight, all of which are critical outcomes for adults with type 2 diabetes. Carbohydrate intake impacts postprandial glycemia more than any other dietary factor. The American Diabetes Association now recommends a very low–carbohydrate diet, because of its ability to improve glycemic control, for the treatment of type 2 diabetes. However, typical nutrition-focused interventions can be burdensome, as the interventions often have complex instructions and require changing one’s diet completely. Additionally, adults with type 2 diabetes and persistent hyperglycemia may be more likely to have low health literacy levels, which can be a barrier to adherence to complex interventions.

This study aimed to evaluate the effectiveness of a digital, small-steps intervention that focuses on implementing a very low–carbohydrate dietary pattern specifically at breakfast for adults with type 2 diabetes and persistent hyperglycemia. The goal is to determine whether this targeted dietary modification can lead to reductions in hemoglobin A1c levels and decreased use of antihyperglycemic medications, without requiring participants to change their entire diet.

The Breakfast Study will enroll adults with a hemoglobin A1c (HbA1c) of 7.0% or higher to our online, 4-month intervention, which will teach participants to change their breakfasts to be very low in carbohydrates. We will measure acceptability and feasibility, plus critical efficacy outcomes, such as changes in HbA1c, antihyperglycemic medications, glycemic variability, body weight, blood pressure, and lipids. We will also test whether factors such as sex and baseline insulin resistance significantly moderate the impact of the intervention on change in HbA1c and antihyperglycemic medications. If the results are promising, we will conduct a follow-up, powered, longer randomized controlled trial of this approach. As the prevalence of type 2 diabetes and the understanding of personalized interventions continue to increase, there is a critical need to provide additional effective options for population-level type 2 diabetes treatment strategies, especially for adults with type 2 diabetes and persistent hyperglycemia.

As of October 2025, we have enrolled 119 participants. The results will be published separately.

The Breakfast Study is a nonrandomized, pre-post trial to assess the acceptability, feasibility, and preliminary effectiveness of an accessible, very low–carbohydrate breakfast for adults with type 2 diabetes and persistent hyperglycemia. This study could provide support for continued research investigating how to lower barriers to dietary interventions for type 2 diabetes.

ClinicalTrials.gov NCT05986097; https://clinicaltrials.gov/study/NCT05986097

DERR1-10.2196/81041

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