The Breakfast Study

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

The investigators will conduct 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 will measure acceptability and feasibility, plus critical efficacy outcomes, such as changes in HbA1c, anti-hyperglycemic medications, glycemic variability, body weight, blood pressure, and lipids.

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 8.0% 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 hypothesize 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 will conduct 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 will measure 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 will also test 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.

Materials will encourage 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.

This will be measured with an Abbott Libre Pro continuous glucose monitoring device on participants' upper arm and the information on the sensor is blinded to participants. The monitoring device will record participants' glucose levels in the interstitial fluid by a glucose oxidase method every 15 minutes, continuously for 14 days at each time point. The glucose variability and the proportion of time spent in the euglycemic (3-7.8 millimoles per litre (mmol/l)) and hyperglycemic (≥ 11.1 mmol/l for at least 15 minutes) states, following previous standards for interstitial glucose concentrations.

High-sensitivity C-reactive protein will be measured with nephelometric methods utilizing latex particles coated with CRP monoclonal antibodies and standardized against a CRP reference preparation.

Measured with sphygmomanometer, assessed as change in blood pressure (systolic and diastolic blood pressure will both be measured, but systolic blood pressure is the main outcome of interest)

At baseline and 4 months, we will use fasting insulin and glucose to estimate insulin resistance by calculating Homeostatic Model Assessment-Insulin Resistance (HOMA-IR)

Inclusion Criteria: HbA1c 8% 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 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