Análisis de las intenciones de implementación en la alimentación saludable

Résumé

The goal of this research is to promote healthy eating behaviours through the understanding of the psychological mechanisms underlying in healthy-eating diets. The study of the promotion of healthy eating habits is included in the social marketing domain and it seeks business, academic and social benefits. Despite the increasing social interest in healthy eating, when studying the impact of this motivation in specific behaviours, there is a gap: although there are individuals motivated about healthy eating, they are not capable of performing this behaviour. The conceptual framework of this research exhaustively reviews the psychological theories of consumer behaviour, including motivational models, goal models and the psychological intervention of implementation intentions. A systematic review of the existing literature of implementation intentions applied to healthy eating is presented, where results suggest that the effect on complex eating behaviours is smaller than on simple behaviours. However, these results are not conclusive enough. To address this literature gap, two empirical analysis are conducted. The first one is a meta-analysis on the existing literature that studies the effect of implementation intentions on a complex behaviour, fat intake reduction. The effect size found is considered small to medium, with a Cohen's d of .346. Moreover, three possible moderator variables that may influence the process are identified: sample type (healthy versus obese or with health problems individuals), number of behaviours (only fat intake versus fat intake plus other healthy behaviours), and initial training (yes or no). The second empirical work conducted is an experiment aimed to assess the implementation intentions effect on another complex healthy eating behaviour, the increase of fibre intake. The moderating capacity of Initial Training variable is also analysed. After performing statistical analysis (ANOCA and ANCOVA) and structural modelling tests (SEM), the results suggest an increase in fibre consumption in those groups that formulated implementation intentions and/or received an initial training. However, the results are not statistically significant. Therefore, it can be concluded that implementation intentions effect is smaller in complex behaviours than in simple behaviours. Research contributions of this thesis are that implementation intentions have a smaller effect in complex behaviours than in simple behaviours; furthermore, there are three moderating variables (initial training, holistic healthy behaviours and previous health status) that can increase the effect size. Future research should be conducted to study in more depth these and similar variables that could have an effect in the process of implementation intentions on complex behaviours. The results obtained have some important implications. Implementation intentions are an effective tool to promote healthy eating behaviours in society; when those behaviours are complex, the effect increases when combining implementation intentions with other elements such as initial training. This suggests that communication efforts from health authorities would be more effective if they include messages that integrate implementation intentions along with training.