Prevalence and risk factors of stunting and thinness among school adolescents in Zanzibar Island: a school based cross-sectional study

Abstract Background Adolescent malnutrition, including stunting and thinness, has gained significant attention as a critical public health concern due to its implications for growth, development, and future well-being. However, there remains a gap in research regarding the specific risk factors contributing to stunting and thinness among adolescents in Zanzibar Island. Objective This study aimed to assess the prevalence and risk factors associated with stunting and thinness among school adolescents in Zanzibar Island, utilising data from the 2022 Zanzibar Island School Health and Nutrition Survey (ZSHNS). Methods The study employed a cross-sectional design, conducting a secondary analysis of 1,772 records of adolescents aged 10–19 years obtained from the 2022 ZSHNS. Stunting was assessed using height-for-age Z-scores (HAZ < -2), while thinness was measured through BMI-for-age Z-scores (BAZ < -2). Logistic regression analysis was performed to identify risk factors associated with these conditions, with results stratified by variables such as age, sex, residence, and other relevant characteristics. All statistical analyses were carried out using STATA Version 18, and associations were expressed as odds ratios (OR) with 95% confidence intervals (CI). Results The study identified a stunting prevalence of 11.8% and thinness prevalence of 5.5%. Key risk factors for stunting included being in the younger age group (10–14 years) (AOR = 0.02, 95% CI: 0.01–0.05, P < 0.001), male gender (AOR = 1.98, 95% CI: 1.45–2.71, P < 0.001), anemia (AOR = 1.89, 95% CI: 1.40–2.65, P < 0.001), and living in rural areas. Thinness was associated with anemia (AOR = 2.52, 95% CI: 1.31–4.68, P = 0.004), middle-income households (AOR = 1.65, 95% CI: 1.13–2.43, P = 0.009), and residing in Kusini Unguja (AOR = 2.08, 95% CI: 1.01–4.33, P = 0.049). Conclusion Stunting and thinness among adolescents in Zanzibar Island are significantly influenced by age, gender, anemia, household income, and regional disparities. The findings suggest that middle-income households and anemia are key contributors to thinness, while stunting is more prevalent among younger adolescents and males, with rural residence being an additional risk factor. These findings highlight the need for targeted and context-specific interventions that address both socio-demographic and health-related factors to effectively combat adolescent malnutrition in Zanzibar Island effectively.