Abstract
Background: Adequate hydration for preschool children (36-72 months) is critical for their healthy growth, cognitive development, and long-term well-being. However, there is still a lack of reliable baseline data in China to inform water intake guidelines for this age group. Methods: In this study, a cross-sectional analysis was conducted using data from the 2018-2019 Dietary Survey of Infants and Young Children in China, including 676 healthy preschool children. Water and energy intake were estimated using four-day food diaries. Their daily total water intake (TWI) and total energy intake (TEI) were evaluated, and the contributions of beverages and foods to TWI and TEI were analyzed, respectively. The TWI was compared with the adequate intake (AI) set by the Chinese Nutrition Society, and the correlations between water and energy intake were explored. Results: The results show that the median daily TWI was 1218 mL, with 667 mL (55.7%, r = 0.824) from beverages and 520 mL (44.3%, r = 0.691) from foods. Among beverages, plain water (74.4%, r = 0.903) and milk and milk derivatives (MMDs, 20.9%, r = 0.443) were the main contributors, while staple foods, dishes, and soup contributed the majority of the water from foods. Only 19.4% of children's TWI met the AI level, and their water and energy intake was significantly higher than those who did not. The median daily TEI was 994 kcal, with 739 kcal (77.2%, r = 0.806) from foods and 198 kcal (22.8%, r = 0.644) from beverages. MMDs accounted for 83.1% of beverage energy (r = 0.880). Boys consumed more beverages than girls, especially in the 37-48 months group. Conclusions: As the first nationally representative study of TWI among Chinese preschool children, these findings reveal a substantial gap between actual intake and current recommendations, and highlight the need to revise reference values and improve hydration guidance in early childhood.