[The preventive efforts of the Spanish autonomous regions and socio-economic inequality in childhood obesity or overweight].

Objective: To explore trends in childhood overweight/obesity according to socio-economic status and in relation to the preventive effort developed by the Spanish autonomous regions.

Method: A series of multilevel cross-sectional studies were conducted using data from different waves of the Spanish National Health Survey, namely 2003, 2006, 2011 and 2017. Hierarchical logistic regression models were estimated, with individuals (level 1) nested within the region-period of study (level 2) and these, in turn, within the region (level 3).