The PWM can be applied to predict and understand adolescents' eating behaviour. Social-reactive processes, namely willingness and prototype perception, are behavioural determinants that should be considered in theory and as novel targets in health promotion interventions.

The study analyzed associations between actual weight status and weight perceptions with personal resources, physical and psychological health, as well as physical performance among adolescents (N = 5,518; age: 11-17 years). Analyses are based on data from the German Health Interview and Examination Survey for Children and Adolescents (KiGGS). Self-report measures, parental reports, as well as objective test data were considered. Results indicate that weight perceptions, rather than actual weight status, were associated with personal resources, health, and perceived physical performance. Comparing groups, we found that adolescents who felt they had "just the right weight" achieved more favourable results than those who perceived themselves as "too fat", regardless of their actual weight status. However, actual physical performance was predicted better by actual weight status. Furthermore, weight perceptions were found to mediate the link between actual weight status and all the assessed outcomes (personal resources, health, and physical performance). With respect to self-reports, the mediational effect was consistently stronger for girls, whereas the reverse was true regarding physical performance. Parental reports were not moderated by sex. Findings provide further evidence that among overweight adolescents there are subgroups that differ significantly with regard to risks and resources. Implications for practice are discussed.

Jungen ernähren sich nachweislich ungünstiger als Mädchen. Die vorliegende Studie untersucht die Prototypen-Wahrnehmung als Erklärung für Geschlechterunterschiede im Ernährungsverhalten von Jugendlichen unter Berücksichtigung des Alters. Angenommen wird, dass die Wahrnehmung des typischen ungesunden und gesunden Essers die Geschlechterunterschiede im Ernährungsverhalten mediiert. Weiterhin wird im Sinne einer moderierten Mediation postuliert, dass das Alter den Zusammenhang zwischen Prototypen-Wahrnehmung und Ernährungsverhalten moderiert. Befragt wurden 340 SchülerInnen an Haupt- und Werkrealschulen im Alter von 10 – 17 Jahren zu Ernährungsverhalten und Wahrnehmung von Esser-Prototypen. Im Ergebnis hatten die Jungen ein signifikant ungünstigeres Ernährungsmuster als die Mädchen und sahen den ungesunden Esser positiver sowie den gesunden Esser negativer. Dieser Geschlechterunterschied im Ernährungsverhalten wurde partiell durch die Prototypen-Wahrnehmung mediiert. Dabei wurde der Zusammenhang zwischen der Prototypen-Wahrnehmung des ungesunden Essers und des Ernährungsverhaltens durch das Alter moderiert: Bei älteren Jugendlichen hing die Wahrnehmung des ungesunden Essers stärker mit dem Ernährungsverhalten zusammen als bei jüngeren Jugendlichen. Die Ergebnisse zeigen, wie wichtig es ist, vor allem bei älteren Jungen eine negative Wahrnehmung des ungesunden Essers zu fördern, mit dem Ziel das Ernährungsverhalten im Jugendalter zu verbessern.

The amount of fluid intake should be adequate and moreover the time span between intake and cognitive efforts should be as short as possible. Schoolchildren are thus recommended to drink at regular intervals and also during lessons.

Abstract. Two studies examined the main assumption of the Prototype/Willingness Model for eating behavior. Accordingly, health-behavior in adolescents results from intentional and social-reactive processes, namely behavioral intentions and behavioral willingness. The hypothesis was that willingness explains eating behavior over and above intentions with respect to eating behavior in general and in the peer context. This was tested in a cross-sectional (N = 286) and a longitudinal (N = 335) study. Intentions and willingness were assessed for healthy and unhealthy eating, eating behavior using an eating pattern index, and observed food consumption in the peer context. Willingness explained variance in eating behavior over and above intentions. Intentional as well as social-reactive processes contribute to adolescents’ eating behavior. Implications for practice are discussed.