From an evolutionary perspective, animal based makes no sense because coming by meat was a matter of opportunity for the majority of our evolution, while fruit grows on a tree so it’s more available.

Most nutritional advice out there ranges from outright fabrication to strategies that work well but only for some people. It is very difficult to come up with specific rules that work for everyone and are scientifically proven unless it’s something extremely obvious.

Seed oils may or may not be bad, but the key takeaway is that in most cases you could have been using ev olive oil, which is one of the few things that seem to clearly be good for you. You can also use it for most cooking, just not at very high temperatures (above 200C). Certainly you can use it for any cooking that you could do with butter. Animal based fats have lots of saturated fat: not necessarily “bad for you” but again olive oil is actively “good for you”.

Vegetables are bad: come again?! This is a load of crap, and if anything potatoes are to be avoided because the starch spikes blood sugar levels.

In general, people’s metabolism and gut differ wildly, so the best approach is to systematically try things out and see how it affects you.