I am well aware of the truth of what you say about churches departing from the faith concerning homosexuality, etc., the most serious departure I have found being the concept that Jesus was not resurrected bodily (believe it or not this is taught by some Christian pastors such as Marcus Borg and others who have influence).

But I have not found (perhaps because not looking) a church or denomination pushing mandatory veganism.  I am curious as to where this may be found.

My church parish is so far from vegan that I would say, rather, that they are junk food supporters.  At the very least one may say that they are oblivious of
"food additives" that are poisonous and do not care a hoot how much saturated fat and over-salt their potlucks provide.  I cannot eat at their potlucks unless I
bring my lunch.  Their efforts to barbecue everything with solvent-saturated smoke is not a help either.

I am certainly aware of the dangers of veganism, as my stepdaughter was a vegan for decades and now has osteoporosis which is far advanced for her years.
She is no longer a vegan.  Her mother, too, actually succumbed from the side effects of a vegan diet, which crept up on her and finally "got her", starting with
extreme osteoporosis.  I believe some vegans avoid osteo by taking capsules of B12 (which is missing in the vegan diet) but still I think it is an unhealthy diet.

Thank you Keven or anyone who knows of compulsory veganism being sponsored by churches.

For those not in the know, veganism is much more extreme than vegetarianism.  Typical vegetarians avoid meat taken from living creatures, but most of them drink milk and eat eggs.  There are all "levels" of vegetarianism, with some of them eating fish but no land-based meat.  Some avoid eggs but use dairy products.  If one uses dairy and eggs one can avoid the B-12 problem of veganism. This is complicated by the widespread push against "diary," which some people think is bad in itself.  Dairy is bad only if you have the genes to react badly to dairy.  Those of us with pro-dairy genes do well on dairy (many of us are anthropologically linked to the "alpine stock" of Switzerland, who used lots of diary).  I myself eat fowl, diary, and eggs, but get some of my protein from vegetable sources such as beans.
Some bean-eaters must avoid soy, i.e. tofu--it's very complex to understand how people eat and how they should eat!  Daniel of the Bible probably had a vegetarian diet, but he somehow knew how to add to it to avoid illness and live to a very ripe old age.)

Mariel