Parental employment during early childhood and overweight at 7-years: findings from the UK Millennium Cohort Study

BACKGROUND There are increasing numbers of families with both parents (or a lone parent) employed, which may impact on the ability of families to support healthy lifestyles for their children. Some studies have linked maternal, but not paternal, employment with childhood overweight, although most have been cross-sectional or reported over short periods. We investigated the relationship between parental employment since infancy and overweight in children at 7-years. We differentiated employment by intensity (hours worked), and examined mutually adjusted associations of cumulative maternal and paternal employment with childhood overweight. METHODS Data on parental employment at 9 months, 3, 5 and 7-years were used to create cumulative measures of maternal, paternal and family employment in the UK Millennium Cohort Study (MCS). Risk ratios (RR) and 95 % confidence intervals (CI) for childhood overweight (including obesity) at age 7 were estimated according to employment, before and after adjustment for potential confounders. RESULTS Compared to continuous non-employment within the family since infancy, any employment of a parent was associated with lower risks of child overweight (e.g. one survey sweep in employment, adjusted RR: 0.71 [0.56-0.90]). Prolonged maternal full-time employment, however, was associated with elevated risks (four sweeps in full-time employment versus never, adjusted RR: 1.46 [1.20-1.78]). There was no equivalent association with paternal full-time employment. When limited to couple families, and adjusting for cumulative full-time employment of both parents and confounders, the risk of overweight at 7-years associated with continuous maternal full-time employment was not attenuated (adjusted RR: 1.71 [1.38-2.11]), and the association with paternal employment remained non-significant. CONCLUSIONS Children living in workless households or where two parents are full-time employed have increased risks of overweight. These findings may imply the need for changes to enable parents to maintain healthy lifestyles for their children in the face of wider obesogenic influences.