[Socioeconomic vulnerability and obesity in Chilean schoolchildren attending first grade: comparison between 2009 and 2013].

INTRODUCTION: Although obesity is related to socioeconomic level, studies are inconclusive.

OBJECTIVES: To determine obesity risk according to socioeconomic vulnerability among Chilean children (1st grade) in 2009 and 2013 and assess its change during that period, by sex and geographical area.

PATIENTS AND METHOD: Cross-sectional study (N = 175,462 in 2009) and (N = 189,055 in 2013) which included: weight, height, rural / urban, gender and vulnerability obtained from JUNAEB's survey. BMI Z, % obesity and 3 categories of vulnerability (very vulnerable, moderate, non-vulnerable) were determined. For the descriptive analyses, we used t tests and for predictor variables (2 categories of vulnerability) and outcome (obesity) by sex and area, we used %2. Logistic regression models determined OR to develop obesity by.

RESULTS: % obesity was 19.6% and 24.1% in 2009 and 2013, higher in boys. In urban and rural areas respectively, OR to develop obesity were: 0.85 (0.82-0.88) and 0.70 (0.64-0.75) in the most vulnerable students and 0.94 (0.91-0.97) and 0.81 (0.74-0.88) in those with moderate vulnerability in 2009 and 0.96 (0.93-0.98) and 0.89 (0.82-0.96) in the most vulnerable students and 0.99 (0.96-1.02) and 0.94 (0.86-1.02) in students with moderate vulnerability in 2013. The highest increase in obesity was observed among the most vulnerable group from rural areas (16, 6 to 24.3%). vulnerability.

CONCLUSION: The non-vulnerable group had the highest % obesity. Although the most vulnerable students in rural areas had the lowest obesity risk in both years, the highest increase in obesity during the period, occurred in that group.