Trajectories of weight disturbances during adolescence in relation to gender in a Swedish cohort.

Aim: To explore developmental trajectories among adolescents of thinness and overweight in relation to gender.

Methods: A group-based procedure was used to determine patterns of weight disturbances in a school-based sample of 3020 Swedish adolescents followed from age 11 to 18. A sensitivity analysis was performed to compensate for an increasing number of missing height and weight data after grade 8.

Results: Six trajectories represented the best description of developmental weight disturbances with the exception of thinness among boys, which was best described by four trajectories. Concerning thinness, 5.9% of girls and 4.2% of boys developed this condition during the study period, while 1.9% of girls and 3.0% of boys recovered from their initial thinness. For overweight, (including obesity) 1.5% of girls and 3.1% of boys developed this weight disturbance during the study period, while 10.1% of girls and 9.3% of boys recovered from overweight/obesity. Non-reporting of height and weight was biased towards an underestimation of the true prevalence of overweight and obesity in girls and of thinness in boys.

Conclusions: Developmental trajectories provide a novel method to describe the dynamics of weight disturbances during adolescence. Similar patterns were found for overweight and thinness in boys and girls but group sizes varied between genders. Non-reporting of height and weight was found in a gender-specific pattern.