title: Prevalence of normal weight obesity in Switzerland: effect of various definitions.
abstract: BACKGROUND
  Normal weight obesity (NWO) is defined as an excessive body fat associated with a normal body mass index (BMI < 25 kg/m(2)), but its prevalence in the general population is unknown.
  
  
  OBJECTIVE
  To assess the prevalence of NWO in Switzerland according to different cut points used to define excess body fat.
  
  
  METHODS
  Cross-sectional study including 3,213 women and 2,912 men aged 35-75 years. Body fat was assessed by bioelectrical impedance analysis and prevalence of NWO was assessed using four previously published definitions for excess body fat.
  
  
  RESULTS
  Percent body fat increased with age: in men, the values (mean +/- SD) were 20.2 +/- 5.4, 23.0 +/- 5.4, 26.3 +/- 5.2 and 28.2 +/- 4.6 for age groups 35-44, 45-54, 55-64 and 65-75 years, respectively; the corresponding values for women were 29.9 +/- 7.8, 33.1 +/- 7.4, 36.7 +/- 7.5 and 39.6 +/- 6.9. In men, prevalence of NWO was <1% irrespective of the definition used. Conversely, in women, a 1- to 20-fold difference (from 1.4 to 27.8%) in NWO prevalence was found. The prevalence of NWO increased with age when age-independent cut points were used in women, but not in men.
  
  
  CONCLUSIONS
  Prevalence of NWO is low in the general population and higher in women than in men. The prevalence is highly dependent on the criteria used to define excess body fat, namely in women. The use of gender- and age-specific cut points to define excess body fat is better than fixed or gender-specific only cut points.
authors.affiliation: Cardiomet, CHUV, Lausanne, Switzerland. pedro-manuel.marques-vidal@chuv.ch
authors.forename: Pedro
authors.initials: P
authors.lastname: Marques-Vidal
authors.forename: Alain
authors.initials: A
authors.lastname: Pécoud
authors.forename: Daniel
authors.initials: D
authors.lastname: Hayoz
authors.forename: Fred
authors.initials: F
authors.lastname: Paccaud
authors.forename: Vincent
authors.initials: V
authors.lastname: Mooser
authors.forename: Gérard
authors.initials: G
authors.lastname: Waeber
authors.forename: Peter
authors.initials: P
authors.lastname: Vollenweider
mesh_terms: D000273:Adipose Tissue / Q000033:anatomy & histology* / Q000378:metabolism; D000328:Adult; D000367:Age Factors; D000368:Aged; D000375:Aging / Q000502:physiology*; D001823:Body Composition / Q000502:physiology*; D015992:Body Mass Index; D001835:Body Weight / Q000502:physiology*; D003430:Cross-Sectional Studies; D017097:Electric Impedance; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000453:epidemiology*; D015995:Prevalence; D012016:Reference Values; D012737:Sex Factors; D013557:Switzerland