Worsening trend of central obesity despite stable or declining body mass index in Hong Kong Chinese between 1996 and 2005.

We analyzed the obesity trends in Hong Kong using data from a health assessment program. We recruited 84 357 subjects (27 452 men and 56 905 women; age: mean+/-s.d. 49.0+/-14.7 years, range 20-98 years) in three phases: (1) April 1996 to August 1997 (n=17 119); (2) February 2001 to December 2002 (n=16 978); and (3) January 2004 to December 2005 (n=50 260). Waist circumferences were available only in phases 2 and 3. Central obesity was defined as waist > or =90 cm in men and > or =80 cm in women. Overweight and obesity (general) were defined as body mass index (BMI) > or =23 and > or =25 kg/m(2), respectively. The age-standardized rate (95% CI) of general obesity was stable in men (31.6% (29.6, 33.7) in 1996 vs 31.0% (30.0, 32.0) in 2005, P: NS) but declined in women (22.4% (21.3, 23.5) in 1996 vs 18.8% (18.2, 19.4) in 2005, P<0.05). The prevalence of central obesity increased from 23.0% (20.6, 25.4) in 2001 to 26.9% (26.0, 27.8) in 2005 in men (P<0.05) and remained stable in women, with corresponding rates of 27.5% (25.8, 29.3) and 26.6% (26.0, 27.3), respectively (P: NS). In summary, despite stable or declining BMI, age-standardized central obesity failed to decline in Hong Kong Chinese women and continued to increase in Chinese men over a 10-year period.