title: Randomization to plant-based dietary approaches leads to larger short-term improvements in Dietary Inflammatory Index scores and macronutrient intake compared with diets that contain meat.
abstract: Studies have examined nutrient differences among people following different plant-based diets. However, all of these studies have been observational. The aim of the present study was to examine differences in nutrient intake and Dietary Inflammatory Index (DII) scores among overweight and obese (body mass index 25.0-49.9 kg/m(2)) adults randomized to receive dietary instruction on a vegan (n = 12), vegetarian (n = 13), pescovegetarian (n = 13), semivegetarian (n = 13), or omnivorous (n = 12) diet during a 6-month randomized controlled trial. Nutrient intake, nutrient adequacy, and DII score were assessed via two 24-hour dietary recalls (Automated Self-Administered 24-Hour Dietary Recall) at baseline and at 2 and 6 months. Differences in nutrient intake and the DII were examined using general linear models with follow-up tests at each time point. We hypothesized that individuals randomized to the vegan diet would have lower DII scores and greater improvements in fiber, carbohydrate, fat, saturated fat, and cholesterol at both 2 and 6 months as compared with the other 4 diets. Participants randomized to the vegan diet had significantly greater changes in most macronutrients at both time points, including fat and saturated fat, as well as cholesterol and, at 2 months, fiber, as compared with most of the other diet groups (Ps < .05). Vegan, vegetarian, and pescovegetarian participants all saw significant improvements in the DII score as compared with semivegetarian participants at 2 months (Ps < .05) with no differences at 6 months. Given the greater impact on macronutrients and the DII during the short term, finding ways to provide support for adoption and maintenance of plant-based dietary approaches, such as vegan and vegetarian diets, should be given consideration.
authors.affiliation: University of South Carolina, Arnold School of Public Health, Department of Health Promotion, Education, and Behavior, 915 Greene St, Room 529, Columbia, SC 29208. Electronic address: brie@sc.edu.
authors.forename: Gabrielle M
authors.initials: GM
authors.lastname: Turner-McGrievy
authors.affiliation: University of South Carolina, Arnold School of Public Health, Department of Epidemiology and Biostatistics, Cancer Prevention and Control Program, 915 Greene St, Columbia, SC 29208.
authors.forename: Michael D
authors.initials: MD
authors.lastname: Wirth
authors.affiliation: University of South Carolina, Arnold School of Public Health, Department of Epidemiology and Biostatistics, Cancer Prevention and Control Program, 915 Greene St, Columbia, SC 29208.
authors.forename: Nitin
authors.initials: N
authors.lastname: Shivappa
authors.affiliation: University of South Carolina, Arnold School of Public Health, Department of Exercise Science, 921 Assembly St, Columbia, SC 29208 USA.
authors.forename: Ellen E
authors.initials: EE
authors.lastname: Wingard
authors.affiliation: University of South Carolina, Arnold School of Public Health, Department of Exercise Science, 921 Assembly St, Columbia, SC 29208 USA.
authors.forename: Raja
authors.initials: R
authors.lastname: Fayad
authors.affiliation: University of South Carolina, Arnold School of Public Health, Department of Exercise Science, 921 Assembly St, Columbia, SC 29208 USA.
authors.forename: Sara
authors.initials: S
authors.lastname: Wilcox
authors.affiliation: University of South Carolina, Arnold School of Public Health, Department of Health Promotion, Education, and Behavior, 915 Greene St, Room 529, Columbia, SC 29208.
authors.forename: Edward A
authors.initials: EA
authors.lastname: Frongillo
authors.affiliation: University of South Carolina, Arnold School of Public Health, Department of Epidemiology and Biostatistics, Cancer Prevention and Control Program, 915 Greene St, Columbia, SC 29208.
authors.forename: James R
authors.initials: JR
authors.lastname: Hébert
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D015992:Body Mass Index; D018752:Diet, Fat-Restricted / Q000379:methods*; D014676:Diet, Vegetarian; D004043:Dietary Fiber / Q000627:therapeutic use; D005500:Follow-Up Studies; D006801:Humans; D007249:Inflammation / Q000097:blood / Q000178:diet therapy*; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D009749:Nutrition Surveys / Q000379:methods; D009765:Obesity / Q000097:blood / Q000178:diet therapy*; D050177:Overweight / Q000097:blood / Q000178:diet therapy*; D013997:Time Factors; D016896:Treatment Outcome; D015431:Weight Loss / Q000187:drug effects; D055815:Young Adult
keywords: Diet; Inflammation; Nutrients; Vegan; Vegetarian