Do working moms cause kids' obesity?

A recent paper, Maternal Employment and Childhood Obesity, suggests they do.

Recent research has found that maternal employment is associated with an increased risk of childhood obesity. .... We find that employed women spend significantly less time cooking, eating with their children, and playing with their children, and are more likely to purchase prepared foods. We find suggestive evidence that these decreases in time are only partly offset by husbands and partners. These findings offer plausible mechanisms for the association of maternal employment with childhood obesity.