Understanding the decision-making processes surrounding fruit and vegetable consumption among adults living in Australia

The health benefits of consuming fruit and vegetables are substantial, yet only 5.6% of all Australians aged 18 years and above currently meet the recommended daily intake [RDI] of two serves of fruit and five serves of vegetables. Social marketing campaigns aimed at motivating increased fruit and vegetable consumption may therefore be of considerable value in helping a larger proportion of the Australian population achieve these RDIs. The efficacy of such campaigns ultimately depends, however, on identifying which decision-making pathways are most likely to increase intended and actual consumption practices among adults living in Australia, and relatively little is known about these decision-making processes. Using the theory of planned behaviour as a theoretical framework, the overarching aim of this thesis was to investigate the motivational antecedents of an individual’s decision to meet the Australian fruit and vegetable RDI guidelines. In Study 1, 38 semi-structured interviews were conducted to elicit salient beliefs about consuming fruit and vegetables. The beliefs elicited in Study 1 were then integrated into the Study 2 face-to-face survey, which was completed by 470 adults residing in three communities within Victoria, Australia. The aims of the Study 2 face-to-face survey were to examine: (i) the predictive utility of the belief-based frameworks underpinning attitude and subjective norm; (ii) the predictive utility of attitude, subjective norm, and perceived behavioural control with respect to intention to meet the RDIs for fruit and vegetables; (iii) the predictive utility of intention and perceived behavioural control with respect to whether individuals met some or none of the RDI guidelines; and (iv) whether these relationships were moderated by SES (household-level and area-level) and the age bands of children living with participants. The relationships between the belief-based frameworks and their theoretical postcedents (i.e., attitude, r²=9.0%; subjective norm, r²=37.4%) were positive and significant. Moreover, attitude, subjective norm, and perceived behavioural control predicted intention (r²=54.7%), with subjective norm having the strongest influence. Finally, intention, but not perceived behavioural control, predicted behaviour (r²=22.4%–31.0%). Significant moderation effects were also found. Specifically, household-level SES moderated the relationships between: (i) attitude and its underlying belief-based structure; (ii) subjective norm and its associated belief-based structure; and (iii) attitude and intention. Conversely, area-level SES only moderated the attitude–intention relationship. Finally, the age band of children living with participants moderated the relationships between: (i) attitude and intention; (ii) subjective norm and intention; and (iii) perceived behavioural control and intention. The findings pertaining to the moderating influence of child age bands are particularly noteworthy as they expand on more traditional views of the food socialisation process, which tend to assume that food consumption practices are only transmitted from adults to children. The findings from this thesis provide insights that could be leveraged by social marketers seeking to develop and implement interventions aimed at improving fruit and vegetable consumption levels in Australia