When mothers work, their kids get fat, writes Tim Harford in Slate, summarizing research by a trio of economists.
They find that children are fatter if their mothers work longer hours. This is true even within families: The sibling who spent more time as a latchkey child will tend to be the fatter one, perhaps because the mother is less able to supervise outdoor play or has less time to cook and therefore buys more fast food. Unfortunately for working mothers who are already struck by guilt, the effects are pretty substantial. A mere 10 hours at work raises the chance of childhood obesity by 1.3 percentage points, which is about 10 percent.
Another study finds that children who watch more fast-food advertising outweigh children who watch less. But are kids fat because they watch TV or do they watch TV because they’re too fat for sports, unathletic or raised by non-soccer parents.