Long-term Impact of a Low-carbohydrate Versus Low-fat Breakfast on Blood Glucose Control in Type 2 Diabetes
Type 2 diabetes (T2D), a prevalent metabolic disorder impacting \>3 million Canadians, is characterized by insulin resistance and high blood glucose. Chronically elevated blood glucose (i.e., hyperglycemia) and swings in glucose (i.e., glucose variability) contribute to complications of T2D. Specifically, post-meal hyperglycemic spikes are independent risk factors for cardiovascular disease and mortality. People with T2D often exhibit a different circadian pattern from healthy individuals, with higher glucose excursions in the morning, after breakfast. This makes breakfast a crucial meal in achieving glycemic control. One strategy to reduce or eliminate this high glucose excursion is to consume a low-carbohydrate breakfast. Our recently published 3-month clinical trial (Oliveira et al., AJCN 2023) - funded by the Egg Farmers of Canada (EFC) \& Egg Nutrition Center (ENC) - highlighted the positive impact of a simple dietary intervention, where individuals were advised to consume an egg-based, low-carbohydrate breakfast. This intervention led to improved glycemic control assessed by continuous glucose monitoring and reduced overall energy and carbohydrate intake when compared to a low-fat guideline breakfast. While we saw a within-group reduction HbA1c in the egg-based low-carbohydrate breakfast group, the between group difference did not reach statistical significance. Since HbA1c reflects the average glucose over the preceding 3 months, likely, our previous study's duration was not long enough to demonstrate significant reductions in HbA1c. For a low-carbohydrate breakfast to be recognized as an evidence-based strategy in nutrition and clinical practice guidelines, a longer-term study that demonstrates reductions in HbA1c is needed. Collectively, our promising early results demonstrate that the time is right and that our team is poised to deliver a longer, well-powered randomized controlled trial (RCT) to solidify low-carbohydrate breakfasts as an evidence-based strategy to improve glucose control and improve health outcomes for people living with T2D.
• i) physician-diagnosed T2D, ii) 30-79 years old and iii) on stable medication for at least 3 months