title: Associations of maternal employment and three-generation families with pre-school children's overweight and obesity in Japan.
abstract: BACKGROUND
  Maternal employment has been shown to be associated with childhood overweight and obesity (Ow/Ob), but the presence of family members who care for children in place of the mothers might influence children's Ow/Ob and lifestyles. The influence of maternal employment on children's Ow/Ob should be examined together with the presence of caregivers such as grandparents.
  
  
  OBJECTIVE
  The effects of maternal employment and the presence of grandparents on lifestyles and Ow/Ob in Japanese pre-school children were investigated.
  
  
  METHODS
  Cross-sectional study on 2114 children aged 3-6 years who attended all childcare facilities in a city and primary caregivers was conducted.
  
  
  METHODS
  Children's weight and height, family environments (family members, maternal employment, single parent, number of siblings and parental Ow/Ob) and lifestyles (dietary, physical activity and sleeping habits) were surveyed using a self-administered questionnaire. Ow/Ob was defined by the International Obesity Task Force cut-offs.
  
  
  RESULTS
  The eligible participants were 1765 children. The prevalence of Ow/Ob was 8.4% in boys and 9.9% in girls. Maternal employment was associated positively with irregular mealtimes, unfixed snacking times, bedtime after 10 p.m. and nighttime sleep duration of less than 10 h, whereas three-generation families were associated negatively with irregular mealtimes after adjustment for children's characteristics and family environments. Irregular mealtimes (OR (95% CI); 2.03 (1.36, 3.06)) and nighttime sleep duration of less than 10 h (1.96 (1.28, 3.01)) were associated with increased risks of being Ow/Ob. Both maternal employment and three-generation families were significantly associated with children's Ow/Ob. However, three-generation families maintained a significant association (1.59 (1.08, 2.35)) after adjustment for maternal employment.
  
  
  CONCLUSIONS
  These study results suggest that the grandparents who care for pre-school children in place of mothers are more likely to contribute to childhood Ow/Ob than maternal employment. The family-focused lifestyle strategies to prevent childhood Ow/Ob must include grandparents who care for children.
authors.affiliation: Department of Health Promotion Science, School of Public Health, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan.
authors.forename: E
authors.initials: E
authors.lastname: Watanabe
authors.forename: J S
authors.initials: JS
authors.lastname: Lee
authors.forename: K
authors.initials: K
authors.lastname: Kawakubo
mesh_terms: D002648:Child; D002652:Child Behavior; D002668:Child Rearing / Q000639:trends; D002675:Child, Preschool; D003430:Cross-Sectional Studies; D004032:Diet / Q000639:trends; D004651:Employment; D005191:Family Characteristics; D005260:Female; D006801:Humans; D007564:Japan / Q000453:epidemiology; D008019:Life Style; D008297:Male; D009035:Mothers / Q000706:statistics & numerical data*; D009765:Obesity / Q000453:epidemiology* / Q000209:etiology; D050177:Overweight / Q000453:epidemiology; D010375:Pedigree; D015995:Prevalence; D012959:Socioeconomic Factors; D014931:Women, Working / Q000706:statistics & numerical data*