Determinants of undernutrition among adolescent school girls aged 15–19 years in West Belessa Woreda, North Gondar Zone, Amhara Region, Ethiopia: a cross-sectional study

Adolescent girls are nutritionally vulnerable, and addressing their needs is essential to breaking the cycle of malnutrition. However, they are often overlooked, leading to significant gaps in knowledge regarding their nutritional status, particularly in the West Belessa District. This study aimed to determine the prevalence and predictors of undernutrition among adolescent schoolgirls aged 15–19 years in West Belessa District, Amhara Region, Ethiopia. This school-based cross-sectional study used multistage stratified sampling to select 544 adolescent girls (aged 15–19 years). Data were collected through face-to-face interviews and anthropometric measurements. Height-for-age z-score (HAZ) and body mass index-for-age z-score (BAZ) were used to determine stunting and thinness, respectively. SPSS version 26 and WHO Anthro Plus software were used for analysis. Logistic regression was used to identify independent predictors of undernutrition, with p < 0.05 considered significant. The prevalence of stunting and thinness was 25.4% (95% CI 21.8–29.3) and 16.7% (95% CI 13.6–20.1), respectively. Significant predictors of stunting included absence of home latrines (AOR = 3.285), poor dietary diversity (AOR = 1.683), lower meal frequency (AOR = 2.282), food insecurity (AOR = 1.849), and lack of media exposure (AOR = 2.241). Thinness was significantly associated with a lack of latrines (AOR = 2.272), absence of waste disposal sites (AOR = 2.482), recent diarrhea (AOR = 0.343), and poor dietary diversity (AOR = 2.148). One-quarter of adolescent girls were stunted, and a significant proportion experienced thinness. Stunting was linked to sanitation, dietary practices, food security, and media access. Thinness was associated with sanitation, recent diarrhea, and dietary diversity. Targeted interventions are urgently needed to improve dietary diversity, promote adequate meal frequency, enhance environmental sanitation and hygiene, strengthen household food security, and increase media exposure for adolescent girls in this population.