Longer hours at the office may be causing your child to gain weight.

New research suggests that when both parents are working and away from their children, their offspring may suffer from childhood obesity, according to working paper by researchers at the IZA — Institute of Labor Economics think-tank in Bonn, Germany The researchers looked at families’ youngest children going to school and the effect parental work had on the older children’s weight, using data from the 1979 cohort of the Bureau of Labor Statistics’ National Longitudinal Survey of Youth, which tracked nearly 10,000 Americans from 1986 to 2014.

Estimates that 10% of the rise in childhood obesity is due to the rise in working mothers may even be too conservative, it found. The study, “Parental Work Hours and Childhood Obesity: Evidence Using Instrumental Variables Related to Sibling School Eligibility,” focused on the rise in recent years of maternal labor, but noted that there was “no evidence” that the effects of maternal and paternal work are significantly different.

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Previous studies suggest mothers’ employment is correlated to childhood obesity, but the reasons are complicated, said Charles Courtemanche, associate professor of economics in the Andrew Young School of Policy Studies at Georgia State University, and one of the researchers of the latest paper. Mothers’ going back into the workforce after their children have gone off to school may contribute to their children’s health habits, but only if fathers continue to work the same or longer hours, Courtemanche said.

Possible reasons include the changes in family routine, diet, and time spent by the parent working. “Parental employment is likely to reduce beneficial routines, such as regular family meals and physical activities with children,” the study concluded. “At the same time, parental employment might lead to unhealthy routines, such as television-watching and restaurant meals.” However, the study also suggests that child care centers may influence a child’s diet and activity and grandparents.

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Childhood obesity has more than tripled since the 1970s, according to the Centers for Disease Control and Prevention, with about one out of five children between the ages of 6 and 19 having obesity. Obesity can be caused from a number of factors, including easy access to fattening foods, and children’s growing interests in video and smartphone or tablet apps instead of exercise (all of which may be exasperated when parents are at work more than they are at home).

The more years a woman worked after her child’s birth, the higher the child’s body-mass index grew, according to a 2011 report by researchers from Cornell University and the University of Chicago. They analyzed children’s routines, television habits and parental supervision. Taryn Morrissey, associate professor of the department of public administration and policy at American University in Washington, D.C. and one of the researchers behind the report, said it was not meant to alarm nor shame working moms but rather suggests a work-family issue for all working families.

Still, many women do more than their fair share of chores at home. A third of mothers spend at least 60 hours a week on household and family chores (11 minutes more than their male counterparts), according to a 2015 RetailMeNot survey. A lot of mothers say one of the biggest arguments they have with their husbands is whether or not they should go back to work, or stay home instead.

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Going to work may be a more attractive option for some parents and their children. Having both mom and dad at work provides more financial stability and freedom for the family and, some studies suggest, lowers the risk of divorce. Parents also make good employees, because they’re productive, have strong multi-tasking abilities and are empathetic.