The double burden of anemia and excess weight among schoolchildren in Southern Peru: prevalence, associated factors, and the school food environment

Background The double burden of malnutrition (DBM) refers to the coexistence of different forms of malnutrition, particularly undernutrition or micronutrient deficiencies alongside overweight or obesity, within individuals, households, or populations. This study aimed to: i) determine the prevalence of the double burden of malnutrition defined as the coexistence of anemia and excess weight, among schoolchildren in southern Peru; ii) investigate factors associated with the double burden of malnutrition, excess weight, and central obesity; and iii) characterize the school food environment. Methods A cross-sectional study was conducted among 656 schoolchildren aged 5–13 years from six schools in the province of Ica, Peru. Height-for-age (HAZ), weight-for-age (WAZ), BMI-for-age (BAZ), waist-to-height ratio (WHtR), and hemoglobin concentration were assessed using standardized criteria. The school food environment was evaluated using a structured observational checklist. Multivariable logistic regression models were used to examine factors associated with DBM, excess weight, and central obesity, while a general linear model assessed factors associated with hemoglobin concentration. Results Stunting (1.4%), underweight (0.5%) and thinness (1.1%) were uncommon, whereas both excess weight and central obesity (WHtR ≥0.5) affected 50.9% of the schoolchildren. Anemia was identified in 23.5% of participants, and the coexistence of anemia and excess weight (DBM) was observed in 9.9%. After adjustment, anemia was independently associated with lower odds of excess weight, whereas urban residence and older age (11–13 years) were associated with lower odds of central obesity. The school food environment was characterized by the widespread availability of energy-dense, ultra-processed foods and the limited availability of healthier alternatives. Conclusion Schoolchildren in the study population exhibited a nutritional profile characterized by the coexistence of anemia and a high burden of excess weight, consistent with nutritional patterns described in populations undergoing the nutrition transition. These findings provide baseline evidence to support integrated school-based nutrition interventions and evidence-based public health policies aimed at addressing multiple forms of malnutrition.