title: Risk of overweight and obesity among semivegetarian, lactovegetarian, and vegan women.
abstract: BACKGROUND
  Observational studies suggest that a plant-based diet is inversely related to body mass index (BMI), overweight, and obesity.
  
  
  OBJECTIVE
  Our objective was to examine the BMI (kg/m(2)) and risk of overweight and obesity of self-defined semivegetarian, lactovegetarian, and vegan women.
  
  
  METHODS
  Data analyzed in this cross-sectional study were from 55459 healthy women participating in the Swedish Mammography Cohort. Women were asked whether they considered themselves to be omnivores (n = 54257), semivegetarians (n = 960), lactovegetarians (n = 159), or vegans (n = 83), and this question was the main exposure variable in this study. In secondary analyses, we reclassified women as lactovegetarians on the basis of food intakes reported on the food-frequency questionnaire.
  
  
  RESULTS
  The prevalence of overweight or obesity (BMI >/= 25) was 40% among omnivores, 29% among both semivegetarians and vegans, and 25% among lactovegetarians. In multivariate, adjusted logistic regression analyses, self-identified vegans had a significantly lower risk of overweight or obesity [odds ratio (OR) = 0.35; 95% CI: 0.18, 0.69] than did omnivores, as did lactovegetarians (OR = 0.54; 95% CI: 0.35, 0.85) and semivegetarians (OR = 0.52; 95% CI: 0.43, 0.62). Risk of overweight or obesity remained significantly lower among lactovegetarians classified on the basis of the food-frequency questionnaire (OR = 0.48; 95% CI: 0.30, 0.78).
  
  
  CONCLUSIONS
  Even if vegetarians consume some animal products, our results suggest that self-identified semivegetarian, lactovegetarian, and vegan women have a lower risk of overweight and obesity than do omnivorous women. The advice to consume more plant foods and less animal products may help individuals control their weight.
authors.affiliation: Jean Mayer US Department of Agriculture Human Nutrition Research Center on Aging at Tufts University, Boston, MA 02111, USA. pknewby@post.harvard.edu
authors.forename: P K
authors.initials: PK
authors.lastname: Newby
authors.forename: Katherine L
authors.initials: KL
authors.lastname: Tucker
authors.forename: Alicja
authors.initials: A
authors.lastname: Wolk
mesh_terms: D000886:Anthropometry; D015331:Cohort Studies; D016001:Confidence Intervals; D003430:Cross-Sectional Studies; D014676:Diet, Vegetarian; D004435:Eating; D005260:Female; D006801:Humans; D016014:Linear Models; D016015:Logistic Models; D008460:Meat; D008875:Middle Aged; D015999:Multivariate Analysis; D009765:Obesity / Q000453:epidemiology* / Q000209:etiology / Q000517:prevention & control; D016017:Odds Ratio; D012307:Risk Factors; D011795:Surveys and Questionnaires; D013548:Sweden / Q000453:epidemiology