title: Evaluation of a validated food frequency questionnaire for self-defined vegans in the United States.
abstract: This study aimed to develop and validate a de novo food frequency questionnaire for self-defined vegans in the United States. Diet histories from pilot samples of vegans and a modified 'Block Method' using seven selected nutrients of concern in vegan diet patterns, were employed to generate the questionnaire food list. Food frequency responses of 100 vegans from 19 different U.S. states were obtained via completed mailed questionnaires and compared to multiple telephone-conducted diet recall interviews. Computerized diet analyses were performed. Correlation coefficients, t-tests, rank, cross-tabulations, and probability tests were used to validate and compare intake estimates and dietary reference intake (DRI) assessment trends between the two methods. A 369-item vegan-specific questionnaire was developed with 252 listed food frequency items. Calorie-adjusted correlation coefficients ranged from r = 0.374 to 0.600 (p < 0.001) for all analyzed nutrients except calcium. Estimates, ranks, trends and higher-level participant percentile placements for Vitamin B12 were similar with both methods. Questionnaire intakes were higher than recalls for most other nutrients. Both methods demonstrated similar trends in DRI adequacy assessment (e.g., significantly inadequate vitamin D intake among vegans). This vegan-specific questionnaire can be a useful assessment tool for health screening initiatives in U.S. vegan communities.
authors.affiliation: Department of Agricultural Economics and Extension, University of the West Indies, St. Augustine, Trinidad and Tobago. patricia.dyett@sta.uwi.edu.
authors.forename: Patricia
authors.initials: P
authors.lastname: Dyett
authors.affiliation: School of Public Health, Loma Linda University, Loma Linda, CA 92350, USA. srajaram@llu.edu.
authors.forename: Sujatha
authors.initials: S
authors.lastname: Rajaram
authors.affiliation: School of Public Health, Loma Linda University, Loma Linda, CA 92350, USA. ehaddad@llu.edu.
authors.forename: Ella H
authors.initials: EH
authors.lastname: Haddad
authors.affiliation: School of Public Health, Loma Linda University, Loma Linda, CA 92350, USA. jsabate@llu.edu.
authors.forename: Joan
authors.initials: J
authors.lastname: Sabate
mesh_terms: D000328:Adult; D000368:Aged; D015992:Body Mass Index; D002136:Calcium, Dietary / Q000008:administration & dosage; D015930:Diet Records; D014676:Diet, Vegetarian; D004044:Dietary Proteins / Q000008:administration & dosage; D002149:Energy Intake; D015525:Fatty Acids, Omega-3 / Q000008:administration & dosage; D005247:Feeding Behavior; D005260:Female; D006801:Humans; D019266:Iron, Dietary / Q000008:administration & dosage; D008019:Life Style; D008297:Male; D011939:Mental Recall; D008875:Middle Aged; D015596:Nutrition Assessment; D010865:Pilot Projects; D015203:Reproducibility of Results; D011795:Surveys and Questionnaires; D014481:United States; D014805:Vitamin B 12 / Q000008:administration & dosage; D014807:Vitamin D / Q000008:administration & dosage; D015032:Zinc / Q000008:administration & dosage
chemical_list: D002136:Calcium, Dietary; D004044:Dietary Proteins; D015525:Fatty Acids, Omega-3; D019266:Iron, Dietary; D014807:Vitamin D; D015032:Zinc; D014805:Vitamin B 12