Longer work hours for moms mean less sleep, higher BMIs for preschoolers

November 20, 2014
Science Daily/University of Illinois at Urbana-Champaign
A link between moms' employment and overweight/obesity in preschoolers has been found by researchers. The study investigated links between mothers' employment status and their children's weight over time, exploring the impact of potential mediators, such as children's sleep and dietary habits, the amount of time they spent watching TV and family mealtime routines.

"The only factor of the four that we investigated that mediated the relationship between maternal employment status and child obesity was how much sleep the child was getting each night," said lead author Katherine E. Speirs, a postdoctoral research associate in human and community development at the University of Illinois.

Sixty-six percent of the mothers in the sample were employed full time, defined as working 35 hours or more per week. Another 18 percent of the women were employed part time, or 20 to 34 hours per week.
Children whose mothers worked full time got fewer hours of sleep than peers whose mothers worked less than 20 hours per week. The children of women who worked full time also tended to have higher BMIs at the second weigh-in.

Just 18 percent of the preschoolers in the sample were getting the 11 to 12 hours of nightly sleep recommended by the National Heart, Lung and Blood Institute, the researchers found.
On average, the children were getting about 9.6 hours of nighttime sleep. Each additional hour of nighttime sleep that a child obtained was associated with a 6.8 percent decrease in their BMI at the second weigh-in, the researchers found.

"We looked at nighttime sleep in particular, because studies show that the amount of nighttime sleep matters for regulating weight," said Liechty, a professor of medicine and of social work.

"We think that it might be the more hours that mothers are working, the less time they have, and there may be some sort of tradeoff going on, 'Do I spend quality time with my child or do we get to bed early?'" Speirs said. "And then in the morning, when mothers leave for work, their children also wake up early to get to day care."

Mothers whose children were enrolled in 32 licensed day care centers in Central Illinois were recruited for the study. Sixty-six percent of the women had college degrees; about a third had household incomes under $40,000 a year, and just over half the sample had household incomes under $70,000 a year. "The challenges of ensuring that children obtain adequate sleep may be even greater for low-income women, who often hold multiple jobs or work rotating shifts or nonstandard hours," Speirs said.

"There are lots of characteristics about mothers' employment that are really important to help us better understand the relationship between mothers' employment status and child obesity, such as whether women are working part time voluntarily or involuntarily, or scheduled or nonscheduled hours," said Wu, a professor of social work. The authors are exploring some of these characteristics and possible links with child obesity in a related study, which is currently underway.
Science Daily/SOURCE :http://www.sciencedaily.com/releases/2014/11/141120153950.htm