title: Changes in individual weight status based on body mass index and waist circumference in Hong Kong Chinese.
abstract: BACKGROUND
  Weight change predicted diseases and mortality. We investigate 3-year changes in individual body mass index (BMI) and waist circumference in Hong Kong Chinese adults.
  
  
  METHODS
  In the Population Health Survey, 7084 adults in 2003 (baseline) were followed up in 2006. Longitudinal anthropometric data were available in 2941 (41.5%) for BMI and 2956 for waist circumference. Weight status and central obesity were based on objectively measured BMI and waist circumference using Asian standards.
  
  
  RESULTS
  Mean BMI (SD) increased from 22.8 (3.62) to 23.1 (3.95) (p<0.001) with 1.3 percentage point increase in prevalence of overweight and obesity (from 44.3% to 45.6%). One in 5 (22.0%) normal or underweight baseline respondents became overweight or obese and a similar proportion (24.8%) of overweight and obese respondents became normal or underweight. Prevalence of central obesity increased from 28.3% to 32.4% (p<0.001) with a non-significantly greater increase in women (30.0% to 38.1%) than men (23.0% to 26.1%) (p=0.63). A higher proportion of centrally obese respondents returned to normal (29.4%) than normal respondents developing central obesity (17.4%).
  
  
  CONCLUSIONS
  This is one of the few studies in Chinese, which found dynamic longitudinal changes (increase/stable/decrease) in individual weight status and waist circumference. Future studies with better follow-up and investigating the causes of such changes are warranted.
authors.affiliation: School of Public Health, University of Hong Kong, Hong Kong, China.
authors.forename: Lai Ming
authors.initials: LM
authors.lastname: Ho
authors.affiliation: School of Nursing, University of Hong Kong, Hong Kong, China.
authors.forename: Man Ping
authors.initials: MP
authors.lastname: Wang
authors.affiliation: School of Public Health, University of Hong Kong, Hong Kong, China.
authors.forename: Sai Yin
authors.initials: SY
authors.lastname: Ho
authors.affiliation: School of Public Health, University of Hong Kong, Hong Kong, China.
authors.forename: Tai Hing
authors.initials: TH
authors.lastname: Lam
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D044466:Asian People; D015992:Body Mass Index; D005260:Female; D005500:Follow-Up Studies; D006723:Hong Kong / Q000453:epidemiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000453:epidemiology*; D015995:Prevalence; D055105:Waist Circumference