The diet of adolescents can be improved by school intervention.

Abstract
OBJECTIVE: To decrease the intake of sucrose, increase the intake of fibre and the consumption of fruit and vegetables among secondary-school pupils. DESIGN: Intervention study among eighth grade pupils during one school year. Data were collected by questionnaires and from a subgroup of pupils by 48 h dietary recall at baseline in spring 2007 and after the intervention in 2008. SETTING: Twelve secondary schools were randomly allocated to intervention (IS) and control schools (CS) within three cities. Intervention included nutrition education and improvement of the food environment focusing particularly on the quality of snacks at school. SUBJECTS: A total of 659 pupils completed the questionnaires and the dietary recall was obtained from 287 pupils both at baseline and follow-up. RESULTS: The frequency of consumption of rye bread increased (P = 0.03) and that of sweets decreased (P = 0.006) among girls in the IS. The intake of sucrose fell among IS pupils, from 12.8 % to 10.5 % of the total energy intake (P = 0.01). Intake of fruit (g/MJ) remained the same in IS, whereas it decreased in CS (P = 0.04). CONCLUSIONS: Sugar intake can be lowered by improving the quality of snacks, but it is more difficult to increase fibre intake and fruit and vegetable consumption unless the content of school lunches can be modified. It is the responsibility of the adults working in schools to create a healthy environment and to make healthy choices easy for pupils.