Low-carbohydrate breakfast helps control blood glucose levels

A high-fat, low-carbohydrate breakfast can help those with type 2 diabetes control blood sugar levels throughout the day, according to a new study published in The American Journal of Clinical Nutrition.

Study participants with well-controlled type 2 completed two experimental feeding days. On the first day, participants ate an omelet for breakfast with less than 10 percent carbohydrates, 85 percent fat, and 15 percent protein. On the second day, participants ate oatmeal and fruit for breakfast with 55 percent carbohydrates, 30 percent fat, and 15 percent protein. Participants were served an identical lunch and dinner on both days. A continuous glucose monitor, a small device that attaches to the abdomen and measures glucose every five minutes, was used to measure blood sugar spikes across the entire day. Participants also self-reported ratings of hunger, fullness, and a desire to eat something sweet or savory.

The researchers found that when participants ate a low carbohydrate breakfast experienced significantly reduced postprandial hyperglycemia, and the blood sugar levels remained steady after lunch and dinner, according to the study abstract. Further, overall postprandial hyperglycemia and glycemic variability were reduced with the low-carbohydrate breakfast. Premeal hunger was also lower before dinner with the low-carbohydrate breakfast than with the high-carbohydrate breakfast.

Jonathan Little, PhD, assistant professor at the University of British Columbia Okanagan in Kelowna, says a large blood sugar spike that follows breakfast is due to the combination of pronounced insulin resistance in the morning in people with type 2 diabetes, and because typical Western breakfast foods, such as cereal, oatmeal, toast and fruit, are high in carbohydrates.

The study concludes that a very low-carbohydrate, high-fat breakfast lowers post-breakfast glucose excursions, and the effects of the simple dietary strategy could be sufficient to lower overall exposure to postprandial hyperglycemia.

"We expected that limiting carbohydrates to less than 10 percent at breakfast would help prevent the spike after this meal," Little said in a statement. "But we were a bit surprised that this had enough of an effect and that the overall glucose control and stability were improved. We know that large swings in blood sugar are damaging to our blood vessels, eyes, and kidneys. The inclusion of a very low-carbohydrate high-fat breakfast meal in type 2 diabetes patients may be a practical and easy way to target the large morning glucose spike and reduce associated complications."

He does note that there was no difference in blood sugar levels in both groups later in the day, suggesting that the effect for reducing overall post-meal glucose spikes can be attributed to the breakfast responses with no evidence that a low-carbohydrate breakfast worsened glucose responses to lunch or dinner.

As another interesting aspect of the research, participants noted that pre-meal hunger and their cravings for sweet foods later in the day tended to be lower if they ate the low-carbohydrate breakfast. Little suggests this change in diet maybe a healthy step for anybody, even those who are not living with diabetes. Researchers recommend long-term interventions for the best results.