The Breakfast Study

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 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.

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
• 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