Abstract:Objective By analyzing the developmental characteristics of bone age in children aged 4-16 in Loudi City, to explore the relationship between body mass index (BMI) and bone age to study the impact of nutritional status on children's growth and development. Methods A retrospective analysis was conducted on the relevant data of a total of 7 222 children aged 4-16 who underwent bone age examinations at Loudi Central Hospital from March 2020 to March 2022 to compare the impact of BMI on bone age in different age-gender groups. Results There was a statistical difference in BAD ［difference between bone age and chronological age］ among different BMI groups (P＜0.01) . Among overweight and obese children, the BAD level of girls tended to be higher than that of boys of the same age group, but the difference was statistically significant only between boys and girls aged 7-11 years (P＜0.01) . Among emaciated children, the BAD level of boys tended to be lower than that of girls of the same age group, but the difference was statistically significant only between boys and girls aged 12 years old (P＜0.01) . Conclusion In some age groups, overweight and obesity have a greater impact on the advanced bone age of girls, and weight loss is more likely to causes delayed BA in boys.