Maternal employment and childhood obesity in China: evidence from the China Health and Nutrition Survey

Abstract

Using five waves from the China Health and Nutrition Survey (CHNS), we investigate the association between maternal employment and obesity in children aged 3–17 in both rural and urban China. Using body mass index (BMI) and waist circumference (WC) as measures for paediatric adiposity, we provide scant evidence for its relation to maternal employment. We also find no strong association between maternal employment and our measures for children’s diet and physical activity. Our study also suggests that grand-parenting could have beneficial effects on childhood obesity.

Keywords:

• maternal employment
• childhood obesity
• diet
• physical activity
• China

JEL Classification:

• I12
• J13
• J22

Acknowledgements

We would also like to thank two anonymous referees for their valuable comments. All remaining errors are our own.

Funding

This research uses data from the CHNS. We thank the National Institute of Nutrition and Food Safety at the Chinese Center for Disease Control and Prevention, the Carolina Population Center at the University of North Carolina at Chapel Hill, and the National Institutes of Health (NIH) (R01-HD30880, DK056350, and R01-HD38700) and Fogarty International Center, National Institutes of Health, for financial support for collecting and analysing the CHNS data. We also thank the China–Japan Friendship Hospital and the Ministry of Health for support of the CHNS 2009. The study is an output of the first author’s (Peng Nie) scholarship from the Food Security Center from the University of Hohenheim, which is part of the German Academic Exchange Service program ‘Exceed’ and is supported by the German Academic Exchange Service and the German Federal Ministry for Economic Cooperation and Development, in cooperation with the Department of Household and Consumer Economics, Institute for Health Care & Public Management, University of Hohenheim.

Notes

¹ More  details are available at http://www.gallup.com/poll/158501/china-outpaces-india-women-workforce.aspx.

² Liu et al. (2013) investigate changes of China’s urban–rural child (below 18 years old) health and nutritional status over the period 1989 to 2006 and find that there is no association of maternal employment status with z-scores of child height-for-age and weight-for-age, and also anthropometric outcomes of being stunted and being underweight.

³ See Greve (2008), Gwozdz et al. (2013), and Scholder (2008) for useful literature reviews of these extant studies.

⁴ Heilongjiang province was introduced as the ninth province in 1997.

⁵ See Liu (2008) and Popkin et al. (2010) for more detailed information about the CHNS.

⁶ In the CHNS, information about physical activities of children (especially time spent on these activities) is available from 2004 onwards. With regards to time devoted to physical activities for children aged below 5 years, the data are mostly unavailable due primarily to large missing values.

⁷ It is worth noting that among 6–17-year-old Chinese, the increase in WC is much larger than that in BMI (Liang et al., 2012).

⁸ We also conducted our analysis with the use of the two-stage estimation procedure proposed by Lewbel (2012). In our case, we adopt childbirth order and year dummies as instrumental candidates and our results show that there is no association between maternal employment and child adiposity. The estimate results of Lewbel’s technique are not reported here, but are available from the authors upon request.

⁹ In our data set, 533 mothers are currently employed but 209 mothers are unemployed in urban areas, while in the rural areas, the number of employed and unemployed mothers are 1531 and 345, respectively.

¹⁰ Results also indicate that parental education is positively associated with child adiposity, which is echoed by some previous studies (Johnson et al., 2006; Lakshman et al., 2013).

¹¹ If child weight is assumed to be a short-term outcome, child height might be a better proxy for long-term effects. Maternal employment may have a large impact on child height through increasing household income and improving child nutritional status. However, in our case, the correlation between maternal employment (including employment participation or working hours) and child height is negligibly small but negative.

¹² Alternatively, we also checked the nonlinearity nexus between MHWs and childhood obesity using MHWs and its squared as well as cubic terms. The conclusions are the same.