TY - JOUR T1 - Leisure-time physical activity dose‑response effects on obesity among US adults: results from the 1999–2006 National Health and Nutrition Examination Survey JF - Journal of Epidemiology and Community Health JO - J Epidemiol Community Health SP - 426 LP - 431 DO - 10.1136/jech.2009.089680 VL - 64 IS - 5 AU - Dong-Chul Seo AU - Kaigang Li Y1 - 2010/05/01 UR - http://jech.bmj.com/content/64/5/426.abstract N2 - Background It is not well established whether total volume of leisure-time physical activity (LTPA) has dose‑response effects on obesity.Methods The dose‑response relationship was examined using 12 227 non-institutionalised individuals, aged 20‑64 years, drawn from the 8 years (1999–2006) of the continuous National Health and Nutrition Examination Survey (NHANES), a nationally representative sample of the US population.Results The age-adjusted prevalence of women's obesity was 41.4% for those with no LTPA in the past month; 39.1% for those who engaged in LTPA but fell short of the recommended minimum amount of LTPA (ie, <450 metabolic equivalent minutes per week (MET min/week)); 31.0% for those who met the recommended minimum guideline (ie, 450 to < 750); 28.0% for those whose LTPA exceeded the minimum guideline but less than the first quartile among the overachievers (ie, 750 to <1260); 23.4% for the overachievers between the first and third quartile (ie, 1260 to <3556); and 19.5% for the overachievers at or above the third quartile (ie, 3556 MET min/week or above). This association was maintained even after occupational physical activity (OPA) was controlled. However, this pattern was not observed for Mexican and black adults and showed a floor effect as LTPA increased.Conclusions There is a crude graded inverse dose‑response relationship between total volume of LTPA and obesity in US adult women, but not in men. Gender and racial/ethnic differences exist in the relationship of accumulated LTPA with obesity due, in part, to differential ratios of LTPA to OPA. ER -