Background: Most studies that assess the effects of breakfast on subsequent mental abilities compared performance in subjects who had or had not consumed this meal. However, characteristics of breakfast itself may induce metabolic and hormonal alterations of the gastrointestinal tract and potentially modify cognitive performance. Moreover, as far as the evidence on the positive effects of having breakfast is becoming more robust, interest may shift to the specific characteristics of an adequate breakfast.
Objective: The objective was to summarize existing evidence on the role of nutrient composition or energy intake at breakfast on the accomplishment of school-related tasks and cognition.
Design: We conducted a systematic review of the literature through the PubMed database.
Results: From the literature search, we identified 102 articles, 15 of which met the inclusion criteria. Of these, 3 studies provided information on the relation between cognitive and academic performance and energy intake at breakfast, 11 provided the same information for the macronutrient composition of breakfast, and 1 investigated both the aspects. Eleven studies considered breakfast meals differing in glycemic index/load. Selected studies were generally carried out in well-nourished children and adults of both sexes from general education. They were mostly experimental studies of short duration and had a limited number of subjects. Cognitive and academic performance were investigated looking at multiple domains, including memory, attention, reasoning, learning, verbal, and math abilities, with a variety of test batteries scheduled at different time points in the morning. Breakfast options differed in terms of included foods and place and time of administration.
Conclusions: There is insufficient quantity and consistency among studies to draw firm conclusions. However, whereas the hypothesis of a better and more sustained performance with a breakfast providing >20% daily energy intake still needs substantiation, there does appear to be emerging, but still equivocal, evidence that a lower postprandial glycemic response is beneficial to cognitive performance.
Alex’s notes: Eat your breakfast dates back to the era of childhood when mom knew best. There is a lot of interest in breakfast and its effects on health and performance (both cognitive and athletic), especially with the rise of the various forms of fasting. Now despite what you may think, everyone eats breakfast because if you didn’t you would die. No, I’m not talking about the morning meal; rather, I’m talking about the meal that breaks your fast. It doesn’t matter whether it comes at 9am, 1pm, or 6pm; the first meal is always – technically – breakfast. However, most still associate it with a morning meal sometime after waking, which is what we are stuck with for this review.
On the more interesting side of things, this review tackles not just breakfast, but also the macronutrient profile of breakfast and its effects on cognitive and academic performance. The authors acknowledge that specific foods and nutrient combinations elicit different physiological responses and will interact with the brain differently. Overall, 15 articles were included in the review with the predominant subjects being school-age children and adolescents, but four studies did look at adults averaging 20, 26, and 63 years of age.
And the results? Oh, that’s the best part. “There was insufﬁcient quantity and consistency among the studies to draw ﬁrm conclusions on the relation between the amount of energy intake at breakfast and breakfast composition and cognitive and academic performance.” It is kind of a letdown to be honest, but you know what it does remind me of? N=1. Everyone is different and if breakfast works for you, then eat it. If you do fine fasting, then fast. There is no one right answer, whether the question is about academics or athletics. As my mentor once said,
“Re”-search will give you an idea of what diet/supplements/exercise strategies may lead to optimal health and performance gains. Yet, it is your own personal “Me”-search that will tell you if the incorporation of any of these diets/supplements/exercises was beneficial or not.