title: Comparative effectiveness of plant-based diets for weight loss: a randomized controlled trial of five different diets.
abstract: OBJECTIVE
  The aim of this study was to determine the effect of plant-based diets on weight loss.
  
  
  METHODS
  Participants were enrolled in a 6-mo, five-arm, randomized controlled trial in 2013 in South Carolina. Participants attended weekly group meetings, with the exception of the omnivorous group, which served as the control and attended monthly meetings augmented with weekly e-mail lessons. All groups attended monthly meetings for the last 4 mo of the study. Diets did not emphasize caloric restriction.
  
  
  RESULTS
  Overweight adults (body mass index 25-49.9 kg/m(2); age 18-65 y, 19% non-white, and 27% men) were randomized to a low-fat, low-glycemic index diet: vegan (n = 12), vegetarian (n = 13), pesco-vegetarian (n = 13), semi-vegetarian (n = 13), or omnivorous (n = 12). Fifty (79%) participants completed the study. In intention-to-treat analysis, the linear trend for weight loss across the five groups was significant at both 2 (P < 0.01) and 6 mo (P < 0.01). At 6 mo, the weight loss in the vegan group (-7.5% ± 4.5%) was significantly different from the omnivorous (-3.1% ± 3.6%; P = 0.03), semi-vegetarian (-3.2% ± 3.8%; P = 0.03), and pesco-vegetarian (-3.2% ± 3.4%; P = 0.03) groups. Vegan participants decreased their fat and saturated fat more than the pesco-vegetarian, semi-vegetarian, and omnivorous groups at both 2 and 6 mo (P < 0.05).
  
  
  CONCLUSIONS
  Vegan diets may result in greater weight loss than more modest recommendations.
authors.affiliation: Department of Health Promotion, Education, and Behavior, Arnold School of Public Health, University of South Carolina, Columbia, South Carolina. Electronic address: Brie@sc.edu.
authors.forename: Gabrielle M
authors.initials: GM
authors.lastname: Turner-McGrievy
authors.affiliation: Department of Health Promotion, Education, and Behavior, Arnold School of Public Health, University of South Carolina, Columbia, South Carolina.
authors.forename: Charis R
authors.initials: CR
authors.lastname: Davidson
authors.affiliation: Department of Exercise Science, Arnold School of Public Health, Public Health Research Center, University of South Carolina, Columbia, South Carolina.
authors.forename: Ellen E
authors.initials: EE
authors.lastname: Wingard
authors.affiliation: Department of Exercise Science, Arnold School of Public Health, Public Health Research Center, University of South Carolina, Columbia, South Carolina.
authors.forename: Sara
authors.initials: S
authors.lastname: Wilcox
authors.affiliation: Department of Health Promotion, Education, and Behavior, Arnold School of Public Health, University of South Carolina, Columbia, South Carolina.
authors.forename: Edward A
authors.initials: EA
authors.lastname: Frongillo
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D015992:Body Mass Index; D031204:Caloric Restriction; D002791:Cholesterol, Dietary / Q000008:administration & dosage; D004038:Diet, Reducing; D014676:Diet, Vegetarian; D004041:Dietary Fats / Q000008:administration & dosage; D004043:Dietary Fiber / Q000008:administration & dosage; D004044:Dietary Proteins / Q000008:administration & dosage; D002149:Energy Intake; D005260:Female; D005500:Follow-Up Studies; D038321:Glycemic Index; D006801:Humans; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000178:diet therapy; D050177:Overweight / Q000178:diet therapy; D012959:Socioeconomic Factors; D015431:Weight Loss; D055815:Young Adult
chemical_list: D002791:Cholesterol, Dietary; D004041:Dietary Fats; D004043:Dietary Fiber; D004044:Dietary Proteins
keywords: Diet; Obesity; Vegan; Vegetarian; Weight loss