[Determinant factors of excess of weight in school children: a multilevel study].
BACKGROUND
Rates of obesity reach high levels in Chile, with geographic, social and school variations.


OBJECTIVE
To identify factors at two levels associated with excessive weight in school children: child-family characteristics and school-neighborhood.


METHODS
Using a cross-sectional and multi-step design, seven counties with the highest prevalence of obesity were identified, and schools were randomly chosen from within the 1st, 3 and 5 quintiles of the school strata (same level of obesity prevalence). Within each school, twelve 2nd grade children were randomly chosen (n =42 schools and 504 students). Nutritional status, food intake, eating habits and physical activity were measured. Socio demographic, economic characteristics and nutritional status of the parents were assessed. Home size and facilities for children physical activities were assessed, as well as school infrastructure and management.


RESULTS
Most of the explained variance (97%) in the Body Mass Index (BMI) was due to individual-level factors: sedentary children behaviour (JS coefficient 1.6, standard error (SE) 0.052), maternal obesity (ss 0.94; SE 0.25), paternal obesity (ss 0.83; SE 0.28) and hours watching television (ss 0.789, SE 0.297). The same risk factors were predictive of obesity: child sedentary behaviours odds ratio (OR): 3-98, 95%) confidence interval (CI): 2.44-6.48, maternal obesity (OR 1.91, CI 1.21-3-02) and being woman (OR 1.75, CI 1.01-2.76).


CONCLUSIONS
BMI and obesity are associated with children behaviour or biological and cultural conditions of their families and not with school characteristics.
Amigo
Hugo
H
Departamento de Nutrición, Facultad de Medicina, Universidad de Chile, Santiago, Chile. hamigo@med.uchile.cl
Bustos
Patricia
P
Erazo
Marcia
M
Cumsille
Patricio
P
Silva
Claudio
C
D017677:Age Distribution; D015992:Body Mass Index; D001835:Body Weight; D002648:Child; D002652:Child Behavior; D003430:Cross-Sectional Studies; D015444:Exercise; D005190:Family; D005247:Feeding Behavior; D005260:Female; D006801:Humans; D007899:Leisure Activities; D008297:Male; D009752:Nutritional Status; D009765:Obesity / Q000209:etiology* / Q000523:psychology; D012307:Risk Factors; D012574:Schools / Q000706:statistics & numerical data*; D017678:Sex Distribution; D012959:Socioeconomic Factors