The nutritional quality of snacking was also significantly related with students’ final GPA as shown in Figure 3. After accounting for the effect of sex, weight status, physical activity, parental education, family structure and iron supplementation in infancy (Table 4), the group snacking on unhealthy foods at home had a final GPA of 490.0 points, on average, whereas participants having healthy snacks at home had a final GPA of 530.1 points (GPA mean difference = −40.1 points; 95% CI: −59.2; −16.9, d = 0.43). When comparing those having unhealthy-to-fair snacks vs. those having healthy snacks at home the GPA mean difference was −27.9 points (95% CI: −43.5; −8.2, d = 0.30). It is worth noting that Cohen’s d coefficients around 0.20 are considered of interest in educational research when they are based on measures of academic achievement . Lastly, the same pattern was observed when the main exposure was the nutritional quality of at-school snacking.