Diet quality, diet motives, and nutrition literacy of vegans, vegetarians, and semi-vegetarians.

Objective: Limited research is available on how motivations to adopt plant-based diets and nutrition literacy influence diet quality. This study assessed diet quality, diet motives and nutrition literacy in vegans, vegetarians, and semi-vegetarians, and investigated predictors of dietary quality.

Design: Cross-sectional study, participants completed an online survey about diet-related motives and nutrition literacy. Dietary intake was assessed with the Diet History Questionnaire III and diet quality was calculated with the Healthy Eating Index (HEI)-2015. A one-way ANCOVA was used to compare diet quality, nutrition literacy, and diet motives among diets. Hierarchical regression analysis was performed to identify significant predictors of diet quality.

Setting: Online survey, participants were recruited through paid targeted social media (Facebook/Instagram) advertising.

Participants: Adults following a plant-based diet, including 117 (52.5%) vegans, 51 (22.9%) vegetarians, and 55 (24.6%) semi-vegetarians.

Results: Vegans had higher HEI-2015 scores (80.8±6.5, p<0.001) compared to vegetarians (75.1±9.1), and semi-vegetarians (76.8±7.5). Most participants (74%) had good nutrition literacy scores. Total nutrition literacy did not differ between groups, but vegans had higher vegetarian nutrition literacy than vegetarians and semi-vegetarians (p<0.001). Ecological welfare, health, and sensory appeal were highly important to all participants. Motives accounted for 12.8% of the variance in diet quality scores. HEI-2015 scores were positively associated with motives of health and natural content, but negatively associated with weight control motivation (all p<0.05).

Conclusions: Individuals following plant-based dietary patterns have high diet quality and nutrition literacy. Messages valuing intrinsic over extrinsic factors may facilitate healthier dietary adherence in this population.