Contribution of socioeconomic status, stature and birth weight to obesity in Sub-Saharan Africa: cross-sectional data from primary school-age children in Cameroon

BACKGROUND The pattern of obesity in relation to socioeconomic status is of public health concern. This study investigates whether the association between height and obesity in children is affected by their socioeconomic background. It also explores the relationship between high birth weight and obesity. METHODS School children, (N=557; 5 to 12 years old) were recruited from randomly selected primary schools in a cross-sectional study including 173 rural and 384 urban children in the North West Region of Cameroon. Socioeconomic status (SES) and birth weight were obtained using a self administered questionnaire. Anthropometric measures included height, weight, BMI, waist circumference and percentage body fat. These measures were transformed into age and sex-standardized variables. Then participants were divided according to quartiles of height SDS. RESULTS The highest frequencies of overweight/obesity (18.8%), abdominal overweight/obesity (10.9%) and high body fat/obesity (12.3%) were observed among the tallest children from a high socioeconomic background. Univariate analyses indicate that children of high SES (39.9%), fourth height quartile (33.1%) and of high birth weight (54.8%) were significantly (p<0.001) more likely to be overweight/obese. Multivariate analyses showed high SES (OR 8.3, 95% CI 3.9-15.4), fourth height quartile (OR 9.1, 95% CI 3.4-16.7) and high birth weight (OR 0.1, 95% CI 0.06-0.2) as independent predictors of overweight/obesity. CONCLUSIONS This study confirms that children coming from a high socioeconomic background and being tall are at particular risk of becoming obese.