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When is breakfast the most important meal of the day?

With an increasing amount of research pointing to benefits of intermittent fasting, breakfast has been shunned by more and more people. But for those with type 2 diabetes, blood sugar is a central issue, and breakfast may play a major role in regulating it.

Study under review: Fasting Until Noon Triggers Increased Postprandial Hyperglycemia and Impaired Insulin Response After Lunch and Dinner in Individuals With Type 2 Diabetes: A Randomized Clinical Trial


The breakfast saga continues! Should you skip it? Should you eat it even if you’re not hungry? A new study on people with type 2 diabetes has shed new light on the lasting effects breakfast may have throughout the entire day, particularly on blood glucose maintenance after a meal. Postprandial hyperglycemia (PPHG), or excessively high blood sugar levels after a meal, can have a major impact on long-term health. In fact (as seen in Figure 1), PPHG is thought to be an even stronger predictor[1] of future cardiovascular events than fasting blood glucose in people with type 2 diabetes, particularly in women. With that in mind, controlling post-meal blood sugar peaks seems to be a prudent target for nutritional interventions in people with type 2 diabetes. As you may have read in last month’s ERD, changing up food order is one way to affect the blood sugar response to a meal. Surprisingly, deciding whether or not to consume breakfast can also have strong implications for blood sugar control even later into the evening.

Figure 1: Relative hazards of cardiovascular disease or death based on postprandial glucose levels after lunch

Reference: Cavelot et al. Diabetes Care. 2011 Oct.

In spite of the fact that intermittent fasting regimens that include fasting until lunch have become glamorized in recent years, skipping breakfast has long[2] been[3] associated with a variety of drawbacks (as seen in Figure 2) such as increased weight gain[4], greater risk for developing type 2 diabetes[5], and decreased cognitive[6] function.

Figure 2: Some possible effects of skipping breakfast

Controlled studies in people who generally skip breakfast have found that compared to eating breakfast (especially one that is high in protein), skipping breakfast often leads to increased hunger[7], reduced feelings of fullness, and greater energy intake later in the day. For people with type 2 diabetes, skipping breakfast is associated with significantly higher[8] blood sugar levels, while consuming a larger breakfast with a smaller dinner has resulted in a significant reduction[9] of blood sugar levels throughout the day. Somewhat paradoxically, eating or skipping breakfast had no effect on weight loss in overweight but otherwise healthy adults that participated in a 2014 study.

Although a growing number of studies are showing beneficial effects of breakfast on glycemic control in people with type 2 diabetes, the relationship between breakfast patterns and PPHG throughout the entire day is not clear. Breakfast skipping has been shown to cause a higher glycemic response after lunch in people with[10] and without[11] diabetes, indicating a second-meal effect. However, the glycemic response after additional meals had yet to be studied, and it was still unknown if breakfast can elicit an additional ‘third-meal’ effect. Therefore, the aim of this recently published study was to examine the postprandial glycemic responses to identical lunch and dinner meals in participants with type 2 diabetes, who had either consumed or skipped breakfast.

Blood sugar rising way above normal after eating (postprandial hyperglycemia, or PPHG) is strongly associated with future cardiovascular disease. While skipping breakfast has been observed to lead to stronger hunger and increased food intake later in the day, its effect on PPHG in people with diabetes isn’t completely clear. The goal of this study was to examine the effect of eating breakfast on PPHG in people with diabetes.

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