title: Joint associations of physical activity and screen time with overweight among japanese adults.
abstract: BACKGROUND
  Although both insufficient physical activity (PA) and high screen time (ST) are independent risk factors for obesity, how the combination of sufficient/insufficient PA and high/low ST could increase obesity risk among the adult population of Japan is not known. This study examined joint associations of PA and ST with overweight among Japanese adults.
  
  
  METHODS
  An Internet-based survey collected data on height, weight, self-reported time spent in PA and ST, and sociodemographic variables from 2832 adults. Respondents were categorized into sufficient PA/low ST, sufficient PA/high ST, insufficient PA/low ST, or insufficient PA/high ST categories as per public PA guidelines and the median of ST. Logistic regression analysis examined the odds ratios (OR) of being overweight (body mass index, ≥ 25 kg/m(2)) according to the categories of PA and ST.
  
  
  RESULTS
  In comparison with the sufficient PA/low ST category, participants in the insufficient PA/high ST category were significantly more likely overweight (OR, 1.48; 95% confidence interval [95%CI), 1.14, 1.93) after adjusting for sociodemographic variables. A significantly higher OR for overweight (including obesity) among insufficient PA/high ST category was also observed in men, but no significant association was found in women.
  
  
  CONCLUSIONS
  Both insufficient PA and prolonged ST contribute to overweight and obesity among Japanese adults. Public health initiatives addressing obesity in Japan need to consider both promoting PA and reducing ST, especially in men.
authors: Graduate School of Sport Sciences, Waseda University, Nakamura Laboratory 2-579-15 Mikajima Tokorozawa, Saitama 359-1192, Japan. anthroliao@fuji.waseda.jp
authors: Yung
authors: Y
authors: Liao
authors: Kazuhiro
authors: K
authors: Harada
authors: Ai
authors: A
authors: Shibata
authors: Kaori
authors: K
authors: Ishii
authors: Koichiro
authors: K
authors: Oka
authors: Yoshio
authors: Y
authors: Nakamura
authors: Takemi
authors: T
authors: Sugiyama
authors: Shigeru
authors: S
authors: Inoue
authors: Teruichi
authors: T
authors: Shimomitsu
mesh_terms: D000328:Adult; D015444:Exercise; D005260:Female; D006293:Health Promotion; D006801:Humans; D020407:Internet; D007564:Japan / Q000453:epidemiology; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000453:epidemiology; D016017:Odds Ratio; D050177:Overweight / Q000453:epidemiology*; D012307:Risk Factors; D057185:Sedentary Behavior; D012737:Sex Factors; D013690:Television