It makes sense. Divorce causes stress. Family wealth may suffer, making healthy eating more difficult. Time pressures and kids shuttling between parents may mean more takeout and drive-through meals. Single moms who work may have no time to cook. The TV as babysitter (chock full of ads for soda, candy, and sugar-sweetened cereals).
I read about this in The Economist magazine. They were reporting on a study published in a medical journal.
Makes sense, but also suggests some remedies. Probably nothing better than youth sports to allow kids to burn off both calories and stress.