The Theory of Planned Behaviour as a determinant of sugar sweetened beverage consumption among Dutch adolescents

This study analyzes the relationship between intention and sugar consumption among Dutch adolescents using Ajzen’s Theory of Planned Behaviour (TPB). According to the theory, one’s intention consists of three components: attitude towards the behaviour, the subjective norms and the perceived behavioural control (Ajzen, 1991). The higher the components the higher one’s intention to perform the behaviour. This study addresses the behaviour: consuming less sugar sweetened beverages (SSB). It was hypothesized that the more one’s attitude, subjective norms and perceived behavioural control are in favour of the behaviour the lower one’s sugar sweetened beverage consumption. This study solely finds evidence for the effects of the indirect attitude and the indirect subjective norm components. The indirect attitude and the indirect subjective norm variables respectively represent the beliefs that adolescents have about the outcomes when they consume less SSB (e.g. losing weight) and the normative expectations of their parents and friends regarding consuming less SSB (e.g. stimulating to consume less sugar). As partly hypothesized, it is found that the more the presumed beliefs are in favour of the behaviour, and therefore the higher indirect attitude score, the lower the final SSB consumption. In addition, the stricter the normative expectations of parents and friends, and therefore the higher the indirect subjective norm score, the higher the final SSB. The latter is in contrast with the hypothesis that higher subjective norms would lead to lower sugar consumption. However, not enough evidence is found to state that either the total attitude, the total subjective norms or the perceived behavioural control component affect the SSB consumption of Dutch adolescents.