title: Obesity among adolescents: sedentary leisure time and sleeping as determinants.
abstract: BACKGROUND
  Over the past 30 years, the prevalence of overweight and obesity in children and adolescents has nearly tripled. Physical inactivity, unbalanced diet, and unhealthy lifestyles may cause lifelong obesity.
  
  
  METHODS
  A representative, national cross-sectional study was carried out between 2006 and 2007 with 40 middle high schools with 384 classes. We used a three-stage stratified systematic sampling design with a probability proportionate to the size from the northern, middle, southern, and eastern areas in Taiwan. Questionnaires were completed by 8640 students (51.7% boys and 48.3% girls) aged between 13 and 16 years.
  
  
  RESULTS
  Obesity was identified in 7.2% of the participants and 16.1% were overweight. Using stepwise logistic regression, we found that those whose fathers or mothers were obese, watched television for more than 2 hours/day on weekdays and slept for less than 7.75 hours/day at weekends had a statistically significantly greater risk of obesity (females: ORs = 3.4, 4.2, 1.8, and 4.2, respectively; P < 0.05; boys: ORs = 2.3, 1.7, 1.4, and 1.6, respectively; P < 0.05).
  
  
  CONCLUSIONS
  To help prevent obesity, strategies are needed to decrease adolescents sedentary leisure time and help them have sufficient sleep. Nurses can play a key role in health promotion in relation to childhood and adolescent obesity.
authors.affiliation: Laboratory of Physical Activity & Obesity Prevention, Institute of Clinical and Community Health Nursing, National Yang-Ming University, Taipei, Taiwan. ymliou@ym.edu.tw
authors.forename: Yiing Mei
authors.initials: YM
authors.lastname: Liou
authors.forename: Tsan-Hon
authors.initials: TH
authors.lastname: Liou
authors.forename: Lu-Chuan
authors.initials: LC
authors.lastname: Chang
mesh_terms: D000293:Adolescent; D004032:Diet; D004812:Epidemiologic Methods; D015444:Exercise; D005260:Female; D006801:Humans; D007899:Leisure Activities; D008297:Male; D009765:Obesity / Q000453:epidemiology / Q000209:etiology*; D050177:Overweight / Q000209:etiology; D010290:Parents; D057185:Sedentary Behavior; D012890:Sleep; D011795:Surveys and Questionnaires; D013624:Taiwan / Q000453:epidemiology; D013690:Television; D013997:Time Factors