title: A shift in the epidemiology of low body mass index in Brazilian adults.
abstract: OBJECTIVE
  To study the prevalence and current predictors of low body mass index (BMI) in a population undergoing a rapid nutritional transition.
  
  
  METHODS
  Population-based cross-sectional study.
  
  
  METHODS
  Individuals living in the urban area of Pelotas, a medium-sized southern Brazilian city, were interviewed at home.
  
  
  METHODS
  A multiple-stage sampling strategy was used. Out of 3372 eligible subjects, 3047 were interviewed. The study was restricted to adults (> or = 20 y).
  
  
  METHODS
  Low BMI was defined as <18.5 kg/m2.
  
  
  RESULTS
  The prevalence of low BMI was 2.7% (95% confidence interval: 2.1; 3.3), higher in women than men (3.8 vs 1.3%; P < 0.001). In the whole sample (men and women combined), living without a partner and current smoking were positively associated with low BMI. Among women, low BMI presented a U-shaped relationship with age and was positively associated with educational level. The prevalence of low BMI in young women was 6.3%, and in highly educated young women was 8.9%.
  
  
  CONCLUSIONS
  Consistently with previous Brazilian studies, a decline in the overall prevalence of low BMI is clear. However, differently from these studies, the predictors of low BMI in women are similar to those observed within developed countries (including low age and high education), possibly indicating an increase in eating disorders.
authors.affiliation: Post-graduate Program in Epidemiology, Federal University of Pelotas, Pelotas, Brazil. prchallal@terra.com.br
authors.forename: P C
authors.initials: PC
authors.lastname: Hallal
authors.forename: J C K
authors.initials: JC
authors.lastname: Wells
authors.forename: A D
authors.initials: AD
authors.lastname: Bertoldi
authors.forename: F K
authors.initials: FK
authors.lastname: Gazalle
authors.forename: M C
authors.initials: MC
authors.lastname: Silva
authors.forename: M R
authors.initials: MR
authors.lastname: Domingues
authors.forename: M L V
authors.initials: ML
authors.lastname: Carret
authors.forename: C L P
authors.initials: CL
authors.lastname: Araújo
authors.forename: D P
authors.initials: DP
authors.lastname: Gigante
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D015992:Body Mass Index; D001938:Brazil / Q000453:epidemiology; D003430:Cross-Sectional Studies; D004522:Educational Status; D005260:Female; D006306:Health Surveys; D006801:Humans; D007407:Interviews as Topic; D008297:Male; D017533:Marital Status; D008875:Middle Aged; D011159:Population Surveillance; D015995:Prevalence; D012907:Smoking; D013851:Thinness / Q000453:epidemiology*