Dimensions of national culture associated with different trajectories of male and female mean body mass index in countries over 25 years.

Cultural determinants of obesity prevalence have been little studied but could explain significant variations in body mass index (BMI) trajectories among countries. This ecological study quantified longitudinal associations between six dimensions of national culture and mean population BMI over 25 years. National mean male and female BMI data 1990 to 2014 provided dependent variables. National dimensions of culture (from the Hofstede database for up to 87 countries) were independent variables: Individualism, Uncertainty avoidance, Indulgence, Long-term orientation, Power distance, and Masculinity. Analyses used mixed models for repeated measures for each dimension of national culture with male and female adult BMI trajectories, controlling for confounders. A higher mean BMI was significantly associated with higher Individualism, Uncertainty avoidance, Indulgence, and Masculine orientation and with lower Power distance (males only) and lower Long-term orientation (males only). Overall, the national cultural dimensions explained 62.4% (males) and 53.5% (females) of the variance in mean BMI among countries. National cultural characteristics, especially Individualism and Uncertainty avoidance, are strongly related to obesity prevalence, explaining over half of the variance among countries. More research and theory development is needed to understand the pathways for these associations so that cultural contexts can be better accounted for in policies, social marketing messages, and community-based actions for obesity prevention.