evidence: Individuals consuming a plant-based diet and mainly vegetarian diet had a lower incidence of COVID-19 even after adjusting for several confounding variables. [...] We combined the vegan and lacto-ovo-vegetarian groups because of the relatively lower sample size of the vegan group. When dietetic groups (omnivorous, vegetarian and flexitarian) were analysed, we observed a lower chance of individuals in the vegetarian and flexitarian groups of having COVID-19 in the crude analysis (OR=0.62, p=0.007 and 0.63, respectively, p=0.054) and in model 1 (OR=0.58, p=0.003 and 0.61, p=0.045, respectively). The lower incidence of COVID-19 in the vegetarian group persisted after applying model 2 (OR=0.61, p=0.008) and model 3 (OR=0.61, p=0.009) (see figure 2B). For the severity of COVID-19, no significant differences were observed between omnivorous and plant-based groups (see figure 2C) or between the three dietetic groups (see figure 2D). [...] Our study provides evidence that individuals with a plant-based diet and mainly a vegetarian diet had a lower incidence of COVID-19 even after accounting for important variables like physical activity, BMI and pre-existing conditions. Those who reported following plant-based diets or vegetarian diets had a higher intake of vegetables, legumes and nuts, and lower intake of dairy and meats. Our results suggest that a plant-based diet and mainly vegetarian diet may be considered for protection against infection with COVID-19.