I was a vegan or vegetarian for a few years, meticulously tracking and being very careful to get all nutrients. It wrecked me. I developed numerous health issues and cognitive dysfunction. Now I eat lots of eggs, butter, only grass fed beef and organ meat a 3-5 times a week, and fish 4-6 times a week, nothing ever factory farmed. My issue was with the scourge of industrialized factory farming. It's still a plant based diet. I eat vast amounts of veggies with each meal as a base and build on that. I had blood panels done on each diet and my health is better, now, than it has ever been, in body and mind. I don't like to put names on diets anymore, because it seems to only cause problems. Some tend to use their diet as ideology. I do not wish to get sucked into the debate, because I see it as a waste of time, and, frankly, nutrition is mostly all relative anyways. But I thought I'd share my experience because it has been so profound for me.
On eating meat, I realize that there is no way, practically, to eat without causing death at some point. I try to take time before every meal to appreciate the massive amount of energy expended to get this food in front of me to eat. Environmentally, supporting grass fed animals, beef in particular, is actually beneficial to the soil. Soil depletion causes massive problems for humanity in many ways. There are books which talk about the rising and falling of civilizations of the past have correlated with the richness and depletion of the soil nutrient density. Grazing animals help to restore the soil, which has many benefits. Directing money towards supporting grass fed meat/local farms means less money for corporations, which has many benefits (less toxins in the environment and food, less pollution, climate change, animal cruelty, etc). When demand goes up for healthier food, corporations will have to change to selling healthier foods, and human health will increase (that's my loose theory, anyways). I could go on and on. And, well honestly, the health benefits makes me a more effective, active human being so that I may hopefully help more people (or try, however pitiful I may be...).
I've refined my diet over the years to fit specifically and treat what health conditions I have. It is always being tweaked. I suppose it is closest to a paleo diet, but I more accurately call it an anti-inflammatory, low toxin, non-GMO, whole foods, as organic as possible, plant based diet with pastured, grass fed animals or wild caught fish. This is what has worked best for me, until it doesn't (if it comes to that).
"Seek truth in meditation, not moldy books. Look in the sky to find the moon, not in the pond."
- Persian proverb