Multimodal Exercise and Nutritional Interventions in Pediatric Cancer: Effects on Physical Function, Body Composition, and Metabolic Health—A Narrative Review

Survival rates in pediatric cancer have increased substantially over recent decades. However, children and survivors frequently experience treatment-related alterations in physical function, body composition, bone health, and metabolic regulation. Chemotherapy, glucocorticoid exposure, physical inactivity, nutritional imbalance, and inflammatory and neuroendocrine disturbances may contribute to reduced lean mass, decreased bone mineral density, sarcopenic obesity, and long-term cardiometabolic risk. This narrative review critically summarizes current evidence on multimodal exercise and nutritional interventions in pediatric oncology, with particular attention to their effects on physical function, body composition, nutritional status, and metabolic health. Literature searches were conducted in PubMed, Scopus, and Web of Science up to April 2026, combining contextual evidence with studies evaluating combined exercise and nutritional strategies. Current evidence suggests that structured and supervised exercise, particularly resistance and combined aerobic–resistance training, is feasible and safe, and may improve cardiorespiratory fitness, muscle strength, functional capacity, and body composition. Nutritional care should be individualized, prioritizing adequate protein intake, micronutrient status, periodic reassessment of energy requirements, and body composition rather than relying on BMI alone. Nevertheless, available findings remain limited by small sample sizes, heterogeneous protocols, variable supervision, inconsistent outcome assessment, and limited long-term follow-up. Integrating exercise, nutrition, and regular monitoring into pediatric oncology care may help mitigate treatment-related functional and metabolic complications. Future studies should prioritize adequately powered randomized trials, standardized intervention protocols, objective monitoring of exercise intensity, harmonized body composition and functional outcomes, and longer follow-up to define clinically applicable multimodal care models.