Doctor: Margaux Robert
Title: Positive psychological determinants of eating behaviour and nutritional status: an epidemiological approach .
Supervisor: Sandrine Peneau
Doctoral school: ED 146 Doctoral school Galilée, University Sorbonne Paris Nord
Date of thesis defense: 11/2022
Jury: Antoine Avignon, Cécile Elsa Dantzer, Sylvie Despres, Fabien Fenouillet, Boris Hansel, Céline Roda.
Food is a major factor in public health, especially because of its impact on chronic diseases. It is determined by many factors, such as psychological factors. Positive psychology in particular has been identified as an interesting resource for public health prevention. However, the associations with food remain partly unknown. The objective of this thesis was to study different positive psychological traits, namely optimism, self-esteem, resilience, gratitude, satisfaction with life, mindfulness, and mastery, and their association with food consumption and behaviors, in the NutriNet-Santé cohort. The positive psychological traits and the different aspects of eating behavior, namely cognitive restriction, emotional eating, uncontrolled eating and eating disorders, were assessed using validated questionnaires (N = 43,622). Food consumption was measured using 24h dietary records, and participant’s height and weight were self-reported. Optimistic participants were less likely to be prone to cognitive restriction, emotional eating, uncontrolled eating and eating disorders, and to be underweight or overweight. However, the effect of self-esteem on body mass index seemed negligible, and the observed associations also depended on baseline body mass index. More resilient individuals were less likely to be prone to emotional eating, eating disorders and eating disorders. They also had a higher overall dietary quality and a lower consumption of ultra-processed foods. Somme associations between resilience and food groups were mediated by emotional eating. Individuals expressing high levels of gratitude were also more likely to have a higher dietary quality, consumed less ultra-processed foods, more plant-based foods, and more organically grown foods. Finally, individuals with positive psychological trait levels were less likely to change their diet during the first COVID-19 lockdown. These results suggest an influence of positive psychological traits on food consumption and eating behaviors, and provide evidence for the consideration of positive psychological traits in nutrition policy prevention strategies.