Combined nutrition and physical activity education for early adolescents with malnutrition: A systematic review of overweight interventions and the undernutrition evidence gap

Early adolescence represents a pivotal stage of growth and development, characterized by profound changes in dietary patterns and physical activity behaviors. Yet, despite the well-documented consequences of both undernutrition and overnutrition, this age group remains largely overlooked in low- and middle-income country settings where the double burden of malnutrition is rapidly intensifying. The primary objective of this systematic review is to determine the effect of combined physical activity and nutrition education interventions among early adolescents experiencing either underweight or overweight, living in socio-economically disadvantaged circumstances. PubMed, Web of Science, Scopus, and LILACS Plus collection were systematically searched and last updated on June18 ^th 2026. The methodological quality of the studies was assessed using the revised Cochrane Risk of Bias tool for randomized trials. The Grading of Recommendations, Assessment, Development, and Evaluation approach was used to assess the quality of evidence.Five studies comprising 960 adolescents all classified as overweight or obese met the inclusion criteria; no studies involving underweight adolescents were identified. Risk of bias was generally low to some concerns. Overall, the evidence suggests that combined physical activity and nutrition education interventions may improve anthropometric indicators, dietary behaviors, physical activity levels and sedentary behaviors among overweight and obese early adolescents. However, the overall certainty of evidence was very low primarily because of substantial heterogeneity and the limited number of available studies.Given the very low certainty of evidence, the effectiveness of combined nutrition and physical activity education interventions among overweight and obese early adolescents living in resource-constrained settings remains uncertain. While positive trends were noted, the highly inconsistent data across a limited number of studies indicate the data should be interpreted with caution. Furthermore, a substantial gap exists regarding underweight early adolescents. To address this, further high-quality trials, are needed particularly in low-income settings. Protocol registration: PROSPERO (CRD42024569008).