Skipping breakfast among 8-9 year old children is associated with teacher-reported but not objectively measured academic performance two years later

Background
Skipping breakfast, habitually and when experimentally manipulated, has been linked in the short-term to poorer academic performance in children. Little is known about the longer-term effects. This study examined whether skipping breakfast at aged 8-9 years predicted poorer academic performance and classroom behavior 2 years later.

Methods
The Longitudinal Study of Australian Children (LSAC) collected data during 2008 (aged 8-9 years) and 2010 (aged 10-11 years). Breakfast consumption was reported by a parent/caregiver on three occasions within 4 weeks during 2008: by face-to-face interview and two subsequent questionnaires. Children who skipped breakfast on at least one of the 3 days were classified as breakfast skippers. During 2010, the child’s teacher assessed their academic performance relative to other children in the same grade (below/far below average; average; above/far above average) and classroom behavior. Objective literacy and numeracy outcomes (reading, writing, spelling, grammar and numeracy, score range 0-1000) were obtained via linkage to Australian standardized national assessment program (NAPLAN) data in Year 5 (aged 10-11 years). Ordinal and linear regression were used, adjusted for sex, age and sociodemographic variables.

Results
At baseline, 243 (10.7%) of the 2280 children skipped breakfast on at least 1 day. Two years later, breakfast skippers were more likely to have poorer teacher-reported reading (RR: 1.18; 95% CI: 1.08, 1.29), mathematics (RR: 1.11; 95% CI: 1.02, 1.20) and overall academic achievement (RR: 1.15; 95% CI: 1.05, 1.25) than non-skippers. In contrast, differences in objective NAPLAN scores were small (<3%), and only one of the five scales (numeracy) was significantly lower among skippers (mean difference − 13.0; 95% CI: -25.6, −0.8). Classroom behavior was similar between skippers and non-skippers.

Conclusion
In this national sample of 8-9 year old Australian children, skipping breakfast occurred at low levels, and showed little association with measured academic performance 2 years later. This contrasted with teacher perceptions of lower academic performance among skippers than non-skippers, most likely reflecting confounding. This underscores the importance of using objective measures of academic performance to avoid inflated effect estimates and, potentially, unnecessary and costly population interventions to increase breakfast consumption.