The interaction role of obesity and pubertal timing on the psychosocial adjustment of adolescent girls: longitudinal data.

OBJECTIVE: The objective of the study was to verify the hypothesis that obesity is associated with pubertal timing, as both factors interact to predict psychosocial adjustment problems in girls.
SUBJECTS: We selected 811 girls who had participated in a longitudinal study on a representative sample of French Canadian children from 1986 to 1997.
METHOD: Only data collected between 1993 and 1996 were analyzed. We classified the participants into three weight categories (normal, overweight, and obese) and pubertal timing (early, on-time, or late-maturing) and compared their internalized and externalized problem behavior and conflict as well as their socioeconomic status. RESULT: We found that (1) early and late-maturing girls are more at risk of being overweight during the whole period of pubertal development as demonstrated by the increasing rate of obesity in these two groups between 11 and 13 y old, and (2) there was an interaction effect between pubertal timing and obesity in predicting problem behavior and conflict. Overweight and obese girls who developed faster or slower than their peers displayed more adjustment problems at 11 and 12 y old. At 13 y old, obesity predicted adjustment problems separately without regard to pubertal timing. Our results suggest that puberty timing is a risk factor for obesity and that both pubertal timing and being overweight predict adjustment problems during all the courses of pubertal development, supporting partially our hypothesis.
CONCLUSION: Programs and interventions must take into account these two factors and adolescents should be monitored throughout all the periods of pubertal development.