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 rates 1 and mothers working outside the home 2 in past 40 years Rationale for relationship Relationship between increased maternal work hours and child and/or adolescent obesity 3-8 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 ( ) and Child Development Survey ( ) 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 > 95 th percentile based on sex and age Modifying variable– Income Based on the poverty level, considered 9 : 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 % of adolescents were obese

RR95% CI Maternal work hrs/wk Paternal work hrs/wk Maternal Work Hours by income 0-200% PL vs not % PL vs. not ≥ 401% PL vs. not 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= )

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

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