Poor Children Get Fat. Yet Not Before the Age of Three

It is common knowledge that due to poor dietary choices and limited sources children of economically disadvantaged families are more likely to be overweight than their age-mates coming from better social backgrounds. A recent study by Rossem, et.al. (Rossem. 2010) found, however, that this trend does not emerge before the age of 3 years:

"Relative to children from mothers with the highest educational level, mean BMI standard deviation scores was lower at age 24 months in children from mothers with the low, mid-low, and mid-high educational level, and in the mid-low group at 36 months (P < .001). Prevalence of overweight was lower in children from mothers with the mid-low educational level at age 24 and 36 months (adjusted odds ratio at 24 months: 0.61; 95% confidence interval: 0.43-0.87 and at 36 months: 0.65; 95% confidence interval: 0.44-0.96) but was not significantly different for the other educational levels. There were no significant differences in childhood overweight by income level." (Rossem. 2010)

In how far the results of a study working with Dutch children (living in a "welfare state")  are representative of the situation in other industrialized nations, where the gap between the poor and the rich is much wider, yet seems questionable.