French youth trends in prevalence of overweight, obesity and underweight from 2008 to 2018.

The prevalence of overweight and obesity were higher in boys (P < 0.0001). Underweight was more prevalent in girls (P < 0.0001). In adolescents aged 16-17 years old, a stabilization was observed for overweight and obesity whereas the prevalence of underweight increased significantly in boys (P < 0.0001). For children and adolescents aged to 10-12 and 13-15 years old, the obesity and overweight decreased significantly while the underweight was increased for both sexes aged 10-12 years (P < 0.0001). Underweight increased in boys aged 13-15 years (P < 0.0001) while that a stagnation was observed in girls. These encouraging results show the permanent need to develop preventive strategies promoting an healthy active living in order to modify the lifestyle for adolescents with underweight, overweight or obesity.