This article analyses the relationship between socio-economic status and the prevalence of overweight and obesity in the primary school population in Costa Rica.

A National School Weight/Height Census was disseminated across Costa Rica in 2016. The percentage of children who were overweight or obese was calculated by sex, age and socio-economic indicators (type of institution: private, public, mix; type of geographic location: rural, urban and the level of development of the district of residence: quartiles). A mixed-effects multinomial logistic regression model and mixed-effects logistic regression model were used to analyse the association between the prevalence of being overweight or obese and district socio-economic status.

The survey was carried out in public and private primary schools across Costa Rica in 2016.

In total, 347 366 students from 6 to 12 years were enrolled in public and private primary schools.

The prevalence of overweight and obesity among children was 34·0 %. Children in private schools were more likely to be overweight or obese than students in public schools (OR = 1·10 [1·07, 1·13]). Additionally, children were less likely to be overweight or obese if attending a school in a district of the lowest socio-economic quartile compared with the highest socio-economic quartile (OR = 0·79 [0·75, 0·83]) and in a rural area compared with the urban area (OR = 0·92 [0·87, 0·97]).

Childhood obesity in Costa Rica continues to be a public health problem. Prevalence of overweight and obesity in children was associated with indicators of higher socio-economic status.