Objective: To understand the relationship among pubertal timing, overweight and obesity, and eating disorders among Bengbu adolescents, and to provide a reference for obesity prevention. Methods: Two nine year schools were conveniently selected in Bengbu, with 683 students from grade 5 to grade 8. Puberty Development Scale (PDS) and Eating Disorders Inventory of Children (EDI-C) subscale were used, height and weight were measured. The associations between obesity, pubertal timing and eating disorders were analyzed. Results: The prevalence of overweight and obesity was higher in boys than that in girls, and the rate of early pubertal timing, drive for thinness score, body dissatisfaction score and total eating disorder score were higher in girls than that in boys( χ 2/t =28.69, 57.99, 3.47, 2.59, 3.30, P <0.05). The differences in rate of overweight and obesity, bulimia score and total eating disorder score were statistically significant by grade( χ 2/F =28.39, 5.11, 3.95, P ＜0.01). There was a positive correlation among overweight obesity and early pubertal timing and eating disorder, and a positive correlation between early pubertal timing and eating disorder( r =0.18, 0.17, 0.14, P < 0.01 ). The mediating effect of early pubertal timing between overweiht, obesity and eating disorders partially contributed 14.25% to the total effect. Conclusion Overweight and obesity is associated with eating disorders, and early pubertal timing partially mediate the association between overweight obesity and eating disorders. Healthy lifestyle should be advocated in family and school to effectively prevent adolescents obesity, pubertal timing, and eating disorders.

Objective: To understand the interrelationships of parental control, peer relationship, and aggressive behavior in junior high school students, in order to provide a theoretical basis for preventing the occurrence of adolescent aggressive behavior. Methods: During June to July, 2022, 2 564 students of grade one to grade three were selected from 6 junior high schools from each of Suzhou and Xuancheng cities in Anhui Province by using convenient cluster random sampling method, and then the questionnaire survey was administered, including the Chinese version of Parent Control Questionnaire, Chinese version of Buss & Perry Aggression Questionnaire and Adolescent Peer Relationship Questionnaire. Results: Boys scored (185.31±27.49, 21.65±7.43, 21.77 ±8.18, 69.50±11.41, 72.39±11.53) higher than girls (178.21±25.13, 20.08±7.09, 20.61±7.62, 66.56± 11.14 , 70.95± 11.84 ) in parental control, father s psychological control, mother s psychological control, father s behavioral control, and mother s behavioral control ( t =8.63, 5.47, 3.70, 6.60, 3.12), while girls scored (48.41±11.26) higher in peer relationship than boys ( 47.13 ± 10.84 ) ( t =-2.95) ( P <0.01). The scores of first grade students in parental control, father s psychological control, mother s psychological control, father s behavior control, peer relationship, and aggressive behavior (184.67±27.18, 21.83± 7.29 , 22.15±8.07, 68.81±10.95, 50.21±9.57, 80.23±17.66) were higher than those of second gradestudents (180.98±25.46, 20.16±7.82, 20.21±7.55, 68.29±11.69, 45.47±11.67, 74.08±17.70) and third grade students (179.21±26.79, 20.53±7.22, 21.17 ± 8.06 , 66.81± 11.39 , 47.54±11.43, 75.75±16.29) ( F =9.44, 12.87, 13.61, 6.84, 42.85, 30.40, P <0.01). The scores of parental control and peer relationship were positively correlated with the scores of aggressive behavior ( r=0.22, 0.47, P <0.01). Peer relationship partially mediate the relationship between parental control and aggressive behavior, with a partial mediation effect value of 0.04, accounting for 26.39% of the total effect of parental control on aggressive behavior. Conclusions High parental control and poor peer relationship are both positively correlated with the level of aggressive behavior. The peer relationship of teenagers should be improved by establishing appropriate parenting style, tackling campus violence, and maintaining good social norms, in order to reduce the occurrence of aggressive behavior among adolescents.