title: Diet and body mass index in 38000 EPIC-Oxford meat-eaters, fish-eaters, vegetarians and vegans.
abstract: OBJECTIVE
  To compare body mass index (BMI) in four diet groups (meat-eaters, fish-eaters, vegetarians and vegans) in the Oxford cohort of the European Prospective Investigation into Cancer and Nutrition (EPIC-Oxford) and to investigate lifestyle and dietary factors associated with any observed differences.
  
  
  METHODS
  Cross-sectional analysis of self-reported dietary, anthropometric and lifestyle data.
  
  
  METHODS
  A total of 37875 healthy men and women aged 20-97 y participating in EPIC-Oxford.
  
  
  RESULTS
  Age-adjusted mean BMI was significantly different between the four diet groups, being highest in the meat-eaters (24.41 kg/m(2) in men, 23.52 kg/m(2) in women) and lowest in the vegans (22.49 kg/m(2) in men, 21.98 kg/m(2) in women). Fish-eaters and vegetarians had similar, intermediate mean BMI. Differences in lifestyle factors including smoking, physical activity and education level accounted for less than 5% of the difference in mean age-adjusted BMI between meat-eaters and vegans, whereas differences in macronutrient intake accounted for about half of the difference. High protein (as percent energy) and low fibre intakes were the dietary factors most strongly and consistently associated with increasing BMI both between and within the diet groups.
  
  
  CONCLUSIONS
  Fish-eaters, vegetarians and especially vegans had lower BMI than meat-eaters. Differences in macronutrient intakes accounted for about half the difference in mean BMI between vegans and meat-eaters. High protein and low fibre intakes were the factors most strongly associated with increasing BMI.
authors.affiliation: Cancer Research UK Epidemiology Unit, University of Oxford, Oxford, UK. elizabeth.spencer@cancer.org.uk
authors.forename: E A
authors.initials: EA
authors.lastname: Spencer
authors.forename: P N
authors.initials: PN
authors.lastname: Appleby
authors.forename: G K
authors.initials: GK
authors.lastname: Davey
authors.forename: T J
authors.initials: TJ
authors.lastname: Key
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000818:Animals; D015992:Body Mass Index; D015331:Cohort Studies; D003430:Cross-Sectional Studies; D004034:Diet Surveys; D014676:Diet, Vegetarian; D005247:Feeding Behavior; D005260:Female; D005399:Fishes; D006801:Humans; D008297:Male; D008460:Meat; D008875:Middle Aged