Many have attacked the move as an overreach, with the state inappropriately moving a child out of his mother’s house. Ethical issues aside, the case raises an interesting policy question: Will it work? How much do parents influence their children’s weight?

Researchers don’t have a simple answer to that question, but they have learned that much of a parent’s influence on childhood obesity has to do with genetics rather than environment.

To start, studies have found that, of the many home-environment factors at play, maternal obesity is the best predictor of childhood obesity, even more so than low family income or less cognitive stimulation.

But more recent research, particularly a highly cited study in the American Journal of Clinical Nutrition, suggested that was more a question of genes than habits. The study, which followed 5,092 pairs of British twins ages 8 to 11, found that the most influence parents have on obesity is actually genetic, a factor of inheritance, rather than the environment. “Contrary to widespread assumptions about the influence of the family environment, living in the same home in childhood appears to confer little similarity in adult BMI [body mass index],” authors Jane Wardle, Susan Carnell, Claire Haworth and Robert Plomin write.

The research raises one key question: If obesity is genetic, why has it increased so much in recent years? The researchers explain that, some of the genetic predispositions for obesity have existed for awhile. But changes to our food environment, like the proliferation of fast food, have enabled those predispositions to become more powerful.

“Although contemporary environments have made today’s children fatter than were children 20 years ago, the primary explanation for variations within the population, then and now, is genetic differences between individual children,” they write.

To be sure, environmental factors such as television watching, food consumption and physical activity matter, too. And so do very early parenting decisions: bottle-feeding as a baby, for example, is associated with a higher rate of obesity than breastfeeding. Schools, particularly with the food they serve and recess time they provide, play a role, too. The research on parental influences on childhood obesity suggests that childhood obesity is a complex, multi-faceted issue where even a parent’s own influence — her own genes — are a factor she can’t control.