To identify optimal recommendations for 24-hour movement behaviors in relation to obesity indicators among children and adolescents, so as to provide scientific evidences for targeted obesity prevention strategies.

From April to June 2024, 242 participants (96 children aged 6-11, 146 adolescents aged 12-18) were recruited from two schools(one combined junior and senior high school, one consistent school for 12 years) in Tianjin for performing physical examination. Obesity indicators including body mass index Z-scores (BMI Z), waist-to-hip ratio (WHR), body fat percentage (FAT), and fat mass index (FMI) were measured. Measurement of 24-hour movement behaviors using an accelerometer, comprised moderate-to-vigorous physical activity (MVPA), light physical activity (LPA), sedentary behavior (SB), and sleep (SLP). The optimal movement duration and interval for children and adolescents were determined through optimal time zone analysis.

Significant associations were found between 24-hour movement behaviors and BMI Z(F=2.35) and WHR (F=3.55) in children, as well as BMI Z(F=3.57), FAT (F=2.44), and WHR (F=3.61) in adolescents (all P < 0.05). The results of optimal time zone analysis showed that optimal daily durations were MVPA 63(40-70) min, LPA 257(220-270) min, SB 467(390-600) min, SLP 653(590-680) min for children, and MVPA 65(40-70) min, LPA 262(220-270) min, SB 484(440-600) min, SLP 629(510-670) min for adolescents.

The recommended amount of 24-hour movement for children and adolescents based on obesity indicators could provide reference for informing the development of Chinese-specific guidelines, and promote healthy lifestyles among children and adolescents.