Total Water Intake and Total Fluid Intake Worldwide: A Systematic Literature Review in Children and Adolescents

Background: Investigating fluid consumption among children and adolescents poses a challenge due to varying dietary behaviors and hydration needs. This systematic review aims to assess total water intake (TWI) and total fluid intake (TFI) in children and adolescents, focusing on gender differences and adherence to reference values proposed by the European Food Safety Authority (EFSA) and the Institute of Medicine (IOM). Methods: A systematic literature search of PubMed, Scopus, and Scholar was conducted to identify studies published between 2004 and 2024 reporting on TWI and TFI for children and adolescents. Studies were included if they reported fluid intake data in healthy populations, provided quantitative measures of TWI or TFI, and aligned with the EFSA or IOM reference values. From 8731 initial articles, 24 studies met the inclusion criteria. Data were synthesized narratively, and compliance with hydration guidelines was assessed. Results: The review included 24 studies, encompassing 16,254 children and 15,367 adolescents. The majority of participants failed to meet the recommended guidelines. Only one study reported compliance with the recommended TWI values, while four studies in children and four in adolescents showed adherence to the recommended TFI values. Conclusions: The results underscore a widespread inadequacy in achieving the hydration guidelines among children and adolescents, emphasizing the need for targeted interventions to improve fluid intake. Public health interventions are needed to promote adequate fluid intake, particularly in populations at risk of dehydration-related health outcomes. Future research should focus on identifying barriers to adequate hydration and developing targeted strategies to improve fluid intake behaviors.