Generally speaking youtube fruitarians tend to be the least healthy looking of the diet people online. Vegans and vegetarians are often bloated to different degrees, but seem a bit less likely to completely waste away or have their teeth rot out.
Discussion
Fat is an essential nutrient, and even if they get enough, vegans and vegetarians (to a lesser degree if they use butter and ghee for everything) it is likely coming from seed oils (machine oils), which are a virtually guaranteed way to bring about disease by degenerating the body at a cellular level.