Parents’ Working Hours and Childhood Obesity

Two recent analyses point to a relationship between the hours parents work and a child’s risk of obesity. A small correlation between parents working and childhood obesity risk is not especially new. What is new is a deeper look at the potential for a cause and effect relationship. Charles Courtemanche believes that he and his colleagues have found an important effect:

We found that greater parental work hours lead to large increases in children’s body mass index (BMI) and probabilities of being overweight and obese. The results imply that the increase in parents’ labor force participation accounts for more than ten percent of the concurrent rise in childhood obesity. We found no evidence that mothers’ and fathers’ work hours affect children’s weight differently. We also found that the effect of parental work hours on children’s weight is concentrated among advantaged households, as measured by an index reflecting parents’ education, race and the mother’s marital status.

Looking at Changes in Work and BMI Over Time

Courtemanche used longitudinal data to get a better fix on this relationship. He notes that parents start working more hours when children enter school. He and his colleagues used an instrumental variables model to sort out the effects of different factors like education, race, and marital status. In the end, they found larger effects than prior studies have shown.

The point, says Courtemanche, is not that dual-income families are the problem. The real point is a deeper understanding of how obesity has risen as a byproduct of complex social and technical and social changes.

A Threshold Effect?

Work published by Jianghong Li and colleagues suggests a threshold effect. They focused more on the working hours of mothers. For preschool children, they found a lower risk of obesity if mothers worked less than 24 hours weekly.

For older children (8-14 years), they found a more complex relationship. They saw more more obesity in mothers who worked more than 40 hours or less than 35. These longitudinal data come from Australia.

It’s also worth noting that they saw a greater effect in low-to-medium income families.

These studies are very different. But they have important similarities. Because they’re longitudinal, they can tell us more than a simple snapshot can. Even so, they can only suggest the possibility of causality. They can’t definitively prove it.

It’s clear enough that economic and social stressors can be triggers for obesity. Two parents working long hours would certainly qualify as stressors on a family. The real challenge is to find how these stressors work and how they can be eased.

Click here for the study by Courtemanche and here for the study by Li. For further perspective from Courtemanche, click here.

To Work, photograph © Jake Britton / flickr

Subscribe by email to follow the accumulating evidence and observations that shape our view of health, obesity, and policy.

December 2, 2017