Jordan Lyerly 1 , MSPH, Elizabeth F. Racine 2 , DrPH, James
Laditka 2 , PhD
1 University
of North Carolina Charlotte, Health Psychology
Program
2 University of North Carolina Charlotte, Department of
Public Health Sciences
 Increase in adolescent obesity rates1 and mothers
working outside the home2 in past 40 years
 Rationale for relationship
 Relationship between increased maternal work hours
and child and/or adolescent obesity3-8
 Limitations of existing research
 Are increased hours of maternal employment
associated with an increased rate of adolescent
obesity?
 How does income modify this relationship?
 Data
 From the Panel Survey of Income Dynamics (1997-2005)
and Child Development Survey (1997-2007)
 Design
 Longitudinal
 Participants
 1,108 adolescents and their parents
 Exposure – Maternal employment during childhood
 Hours/week worked by mothers over all 3 time points
(i.e. during childhood)
 Outcome – Adolescent obesity
 Weight and height measured by trained staff
 Considered obese if BMI > 95th percentile based on sex
and age
 Modifying variable– Income
 Based on the poverty level, considered9:
 Low income (< 200% of poverty level)
 Middle income (201%-400% of poverty level)
 High income (>400% poverty level)
 Adjusted discrete time series analysis
 Relative risk
 95% confidence intervals
 Considered several potential covariates
 Maternal age, maternal education, maternal obesity, marital
status, income, child sex, child birth weight, and child
physical activity level
 Interaction between maternal work hours and income
 At baseline (1996)
 Median age of child – 3.5 yrs
 Median maternal work hrs/wk – 30
 Median paternal work hrs/wk – 45
 Income
 42.7% low income
32.0% middle income
 25.4% high income
 In 2007
 20.7% of adolescents were obese
RR
95% CI
Maternal work hrs/wk
1.75
1.01-3.03
Paternal work hrs/wk
1.00
0.61-1.09
0-200% PL vs not
1.45
0.76-2.79
201-400% PL vs. not
2.74
1.15-6.53
≥ 401% PL vs. not
2.17
0.53-8.86
Maternal Work Hours by income
• No interactive effect of paternal work hours
and income on risk of adolescent obesity.
• Maternal obesity was also associated with an
increased risk of adolescent obesity (RR =
2.89, 95% CI=2.16-3.87)
 As maternal work hours increased, the risk of
adolescent obesity increased
 Income modified this relationship
 The association between maternal work hours and
adolescent obesity was particularly strong among
middle income families
 There was no association between paternal work hours
and risk of adolescent obesity
 Strengths
 Longitudinal data with detailed information regarding
employment and income
 Measured height and weight
 Extended research by examining how income modifies
the relationship
 Limitations
 Attrition
 Does not address causal mechanism
 Better support and services for working mothers to
assist in promoting healthy behaviors in children
 Interventions could address ideas and support for:
 Quick and healthy meals
 Healthy eating practices for children
 Focus groups with mothers from different income
levels to understand barriers to healthy eating

1. Ogden, C., & Carroll, M. Prevalence of obesity among children and adolescents: United States,
trends 1963-1965 through 2007-2008. In: NCHS Health and Stats: National Center for Health
Statistics; 2010.

2. US Department of Labor. Women in the laborforce: A databook. http://www.bls.gov/cps/wlfdatabook-2012.pdf

3. Anderson, P. M., Butcher, K. F., & Levine, P. B. (2003). Maternal employment and overweight
children. Journal of Health Economics, 22, 477-504.

4. Fertig, A., Glomm, G., & Tchernis, R. (2009). The connection between maternal employment and
childhood obesity: Inspecting the mechanisms. Review of Economics of the Household, 7, 227-255.

5. Hawkins, S. S., Cole, T. J., & Law, C. (2008). Maternal employment and early childhood overweight:
Findings from the UK Millennium Cohort Study. International Journal of Obesity, 32(1), 30-38.

6. Morrissey, T. W. (2012). Trajectories of growth in body mass index across childhood: Associations
with maternal and paternal employment. Social Science and Medicine, in press.

7. Von Hinke Kessler Scholder, S. (2008). Maternal employment and overweight children: Does
timing matter? Health Economics, 17, 889-906.

8. Ziol-Guest, K. M., Dunifon, R. E., & Kalil, A. (2012). Parental employment and children’s body
weight: Mothers, others, and mechanisms. Social Science and Medicine, in press.

9. National Center for Health Statistics. Health, United States, 2010: With Special Feature on Death
and Dying. Hyattsville, MD. 2011.