We’ve all heard this at least a thousand and one times:

“Breakfast is the most important meal of the day.”

When the adults in our lives say this when we’re little, it makes sense. We need to get fuel in our bellies to give us the energy to make it through the day. As we get older, though, many of us start to rebel. We don’t want what’s offered. We’re not hungry. Or we’re in a hurry and don’t get why we need to eat first thing in the morning. By the time we’re teenagers, it’s almost a lost cause. Every morning in households in the U.S., parents try every trick in the book to get their teen to eat. The beg them to eat something, anything – a granola bar, an apple, a bowl of cereal – before they go to school.

That is, of course, a lighthearted take on this subject. A stereotypical scene of a mom or dad nagging a hurried teen as the teen makes up whatever ridiculous excuse they can for not eating. Parents try but fail. The teens rush off, leaving their homework on the table and harried but happily resigned parents shaking their heads.

But going without breakfast isn’t always funny or lighthearted: some families do not have the means to feed their children a healthy breakfast every day. A recent study in the U.K. examined this situation and its effect on academic achievement.

What they found confirms what parents have been telling kids all along: breakfast is an important meal. And for adolescents, eating breakfast – or not – can have a significant effect on academic achievement.

School Day Breakfast and Academic Performance: The Study

In 2011 and 2012, researchers at Leeds University recruited 311 adolescents age 16-18 to examine the effect of eating breakfast on standardized test scores. While previous studies identified the positive short-term effect of eating breakfast on academic performance – i.e. the effect of breakfast on same-day testing – this study took a different approach. Scientists looked at the effect of long-term breakfast eating habits on performance on the U.K.’s standardized secondary school qualifying exam, the General Certificate of Secondary Education (GCSE). While there’s not a perfect analog for the GCSE in the U.S., think of it like this: if there were one standardized test required to graduate from high school in the U.S., that’s what the GCSE would be.

Here are more details on the study and participants:

• Researchers administered a breakfast consumption questionnaire and asked participants to complete a 7-day food intake diary.
• Breakfast eating habits were classified as follows:
  • Rare: 0-1 school day per week
  • Occasional: 2-3 school days per week
  • Frequent: 4-5 school days per week
• Researchers examined test scores in:
  • Mathematics
  • English
• After eliminating incomplete questionnaires and diaries, researchers ended up with information from a total of 294 participants.
  • 227 girls
  • 67 boys

As a note of interest, a sample size of 294 is more than adequate to make statistical generalizations. While statisticians continue to debate the validity of determining a minimum sample size for various types of experiments, scientists in behavioral health and other medical sciences generally agree that a sample size over 30 (n>30) is a Large Enough Sample Condition.

The Results: Breakfast Matters

Here’s a simple breakdown of what the researchers found.

Breakfast Habits

• Rare (0-1 school days per week): 28.6%
• Frequent (4-5 school days per week): 53.1%
• Occasional (2-3 school days per week: 18.4%

General Effect on Test Scores

• Total overall scores:
  • Compared to students who frequently ate breakfast, students who rarely ate breakfast scored an average of 10.25 points lower on the GCSE.
  • Socioeconomic status had no significant effect on these scores.
• Average scores:
  • Compared to students who frequently ate breakfast, students who rarely ate breakfast received significantly lower average scores on the GCSE.
  • Socioeconomic status had no significant effect on these scores.

Specific Subject Area Effect on Test Scores

• Mathematics:
  • Students who rarely ate breakfast had lower cumulative odds of achieving high scores on the Mathematics segment of the GCSE, compared to students who frequently ate breakfast.
  • Students of low-and middle socioeconomic status who rarely at breakfast had significantly lower cumulative odds of achieving high scores on the Mathematics component of the GCSE, compared to students of low socioeconomic status who frequently ate breakfast.
  • No difference was found when comparing students of high socioeconomic status who frequently ate breakfast with students of high socioeconomic status who rarely ate breakfast.
• English:
  • Students who rarely ate breakfast had significantly lower odds of achieving high scores on the English segment of the GCSE, as compared to students who frequently ate breakfast.
  • Socioeconomic status had no significant effect on these odds.

The results tell a simple story. There’s a measurable difference in academic achievement between students who rarely eat breakfast and students who frequently eat breakfast. This means the effect of breakfast on GCSE scores was only visible – in statistical terms – at the extreme ends of the breakfast-eating scale.

Breakfast Habits and Test Scores: The Implications

Although this study was conducted in the U.K., it’s relevant for parents, teachers, and policymakers in the U.S. as well. Each year, local and state school systems here in the U.S. collect test scores. Then, they send them up the ladder to administrators at the federal level. These scores – and their associated reports and data – have a direct impact on decisions made regarding the overall operating budget of the U.S. Department of Education. These decisions, in turn, have a direct impact on the allocation of essential funds to state and local school districts.

Which means they have a direct impact on anyone involved – as a student, teacher, parent, or administrator – in public education in the U.S.

At the same time, local and state officials collect information on poverty, food availability, and participation in food assistance programs. Then, they send the information up the ladder to administrators at the federal level. This includes the number of students who receive free or reduced lunch. And – apropos to this study – the number of students who participate in free school breakfast programs. These reports have a direct impact on federal funding for food assistance programs for children, adolescents, and adults.

Which means they have a direct impact on the most vulnerable individuals in our society, and how we allocate our tax dollars to support them.

That’s why the information in this study is critical. While it may not seem like it, at first blush, ensuring our children and adolescents have a good breakfast helps us all – not just the students eating breakfast. We’ll conclude with the words of Alex Cunningham, CEO of the non-profit Magic Breakfast, interviewed here:

“This study is a valuable insight, reinforcing the importance of breakfast in boosting pupils’ academic attainment and removing barriers to learning. Education is crucial to a child’s future life success and escaping poverty, therefore ensuring every child has access to a healthy start to the day must be a priority.”