Social vulnerabilities as determinants of overweight in 2-, 4- and 6-year-old Spanish children.

Background: Differences in obesity prevalence among vulnerable groups exist in childhood but it remains unclear whether these differences may be partly determined by socioeconomic status (SES), parental body mass index (BMI) and early life risk factors. We aimed to explore (i) longitudinal associations between belonging to a minority group and being overweight/obese at age 2, 4 and 6 and (ii) associations between accumulation of social vulnerabilities and being overweight/obese at age 6.

Methods: In total, 1031 children (53.8% boys) were evaluated at birth and re-examined during a 6-year follow-up in a representative cohort of Aragon (Spain). Children from minority (vulnerable) groups included Spanish Roma/gypsies, Eastern Europeans, Latin Americans and Africans. Two more vulnerable groups were defined at baseline as children whose parents reported low occupation and education. Ethnicity, SES and parental BMI were collected via interviews. We used logistic mixed-effects models and adjusted for parental BMI, SES, mother's tobacco use, maternal weight gain, birth weight, infant weight gain and breastfeeding practices.

Results: Regardless of confounders, Roma/gypsy children (OR = 4.63;[1.69-12.70]95%CI) and with Latin American background (OR = 3.04;[1.59-5.82]95%CI) were more likely to be overweight/obese at age 6 compared with non-gypsy Spanish group. Children with three vulnerabilities (OR = 2.18;[1.31-3.64]95%CI) were more likely to be overweight/obese at age 6 compared with children with no vulnerabilities. No associations were found between belonging to a minority group and overweight/obesity in children under 6.

Conclusion: Interventions should target Roma/gypsy children, Latin American children and those who accumulate more vulnerabilities as they are at higher risk of being overweight/obese at age 6.