Vegans are actually setting themselves up for malnutrition, according to some articles I've read...they are missing out on some important amino acids which contribute to cell regeneration, and those amino acids can only be found in meat...but every time I look at whichever "news"paper website these days, I read about some "new superfood" and stuff that is "bad for you" and this and that.
Remember when butter was the bad guy? Now, someone actually figured out that beef tallow is not so bad either...best thing to do, IMO, is eat a good balance of meat, breads/starches, greens and other veggies and treat yourself once in a while :-) (btw, I am a retired extended care aide).