Objective: This study compared a motivational intervention based on the Theory of Planned Behaviour (TPB) with a volitional intervention based on implementation intentions.
Design: The study employed a quantitative longitudinal questionnaire design involving two waves of data collection.
Method: Participants (N=198) were randomly allocated to a control group or one of two intervention groups. TPB variables, and fruit and vegetable consumption were assessed at the beginning of the study (time 1) and 2 weeks later (time 2). Experimental group A formed an implementation intention, about how, when and where they could eat five portions a day, whilst experimental group B stated ways they could overcome motivational barriers to eating five portions a day.
Results: Both interventions were found to increase fruit and vegetable consumption significantly, although only the volitional intervention demonstrated a significant increase in fruit and vegetable consumption over the control intervention.
Conclusions: The present study found support for two interventions in increasing fruit and vegetable consumption in children. These findings are encouraging regarding the use of these types of interventions within schools to improve children's eating behaviour.