Publication Date

Spring 2022

Degree Type


Degree Name

Master of Science (MS)


Nutrition, Food Science and Packaging


Giselle Pignotti

Subject Areas



Individuals consuming plant-based diets have shown favorable dietary behaviors and diet quality. However, differences in diet quality considering motivations to adopt plant-based (vegan, vegetarian, and semi-vegetarian) diets and nutrition literacy, are not well known. The primary objective of this study was to assess diet quality, diet motives and nutrition literacy in vegans, vegetarians, and semi-vegetarians. The secondary objective was to investigate the association between diet motives and dietary quality. In this cross-sectional study, 223 participants completed an online survey and food frequency questionnaire. The study used the Healthy Eating Index-2015 to measure dietary quality, the Food Choice Questionnaire to measure diet-related motives, and the Nutrition Literacy Assessment Instrument to measure nutrition literacy. Vegans had higher diet quality (80.8±6.5 out of 100, p<0.001) compared to vegetarians (75.1±9.1), and semi-vegetarians (76.8±7.5). Ethics was the top diet motive for 69.4% of vegetarians, while health was the top motive for 50% of vegans and 45.3% of semi-vegetarians. No differences in nutrition literacy were observed among groups; the overall mean score was 59.0±3.1 (out of 64). An increased importance of health (p=0.004) and natural content (p=0.016) was associated with increased diet quality, whereas an increased importance of sensory appeal (p=0.047) and weight control (p=0.033) was associated with decreased diet quality. Overall, the plant-based population has high diet quality and nutritionliteracy. Future programs can make public health messages that encourage plant-heavy diets more appealing by considering top motives and nutrition literacy.