Revisiting the ‘fat and jolly’ hypothesis: socio-environmental determinants of obesity and depression in Spain

The hypothesis of the reciprocal determination of obesity and depression (OD) epidemics, contrasts with the anecdotal wisdom of a person being ‘jolly and fat’, and calls for a better understanding of any underpinning socioenvironmental determinants. This paper deals with the influence of socioenvironmental factors (mainly social and personal interactions) in explaining the empirical association between OD. We draw upon a unique representative health survey from Spain; a country with a growing prevalence of both OD. We use instrumental variable methods to deal with reverse OD association and the existence of omitted confounding variables as common predictors. We find that in explaining the OD association, socio-environmental factors and especially family interactions appear to play a key intermediate effect rather than socioeconomic position. Finally, we find evidence of the significant gender differences and a particular effect of health-related lifestyles behind the OD association.