Fig. 1.

Flow diagram of information through the different phases of the review: flowchart of the literature search and review process. *Reasons for exclusion: study population not adolescents (adults or young children, n 70); study did not address the main objective of the present review (n 246); study was conducted outside the secondary-school setting (n 14); study was in the form of a poster or a personal opinion publication (n 4); study was in the form of a literature review, eating disorders or PhD thesis (n 4)