Profiles of literacy, dietary habits, and sleep in Portuguese Schoolchildren: A cluster analysis

Background

Food and nutrition literacy, health literacy, diet, and sleep are key determinants of child health. This study identified distinct profiles of these factors, enabling the identification of at-risk subgroups and their characterization according to sociodemographic and behavioral factors.

Methods

The sample comprised 284 students (grades 5–6, aged 9–13 years) from urban, peri-urban, and rural schools in Leiria, Portugal. Sociodemographic and behavioral data were collected. Validated instruments assessed Mediterranean diet adherence (KIDMED), food and nutrition literacy (E-LAN), health literacy (LiSaKIDS), and sleep disturbances (SSR-PT). Variables were standardized (z-scores), and k-means cluster analysis was performed, identifying four clusters based on the elbow method. Clusters were described using means and frequencies/percentages.

Results

Four distinct clusters were identified: Cluster 1 (”Moderately Balanced”, 22.2%), Cluster 2 (”Optimal Profile”, 34.2%), Cluster 3 (”Vulnerable”, 20.1%), and Cluster 4 (”Healthy but Sleep-Challenged”, 23.6%). Cluster 2 exhibited the highest literacy and diet adherence, along with minimal sleep disturbances, primarily comprising 5th-grade urban students. Cluster 3, the most vulnerable, showed significantly lower literacy, poorer diet adherence, and higher sleep disturbances, predominantly affecting boys in peri-urban areas. Cluster 1 fell near the cohort mean, while Cluster 4 combined good literacy and diet with moderate sleep issues, potentially linked to nighttime device use. Healthier clusters were tied to higher parental education and household income, with nighttime device use correlating with increased sleep disturbances, especially in Cluster 3.

Conclusions

Distinct profiles of literacy, diet, and sleep were identified and were shaped by sociodemographic and behavioral factors, supporting the need for targeted, subgroup-specific health promotion strategies in school settings.

Key messages

• Four distinct profiles of literacy, diet, and sleep were identified among schoolchildren, ranging from optimal to vulnerable patterns with clear differences in health behaviors.

• The identified profiles were strongly associated with sociodemographic and behavioral factors, highlighting the need for targeted, subgroup-specific school-based health promotion strategies.