My own experience is that giving up all or even most fats was very bad for my mental and emotional health (years of depression and anxiety, improved greatly by going to a more traditional diet), and eating eggs regularly made me much healthier; it fixed my low HDL cholesterol, for example.
I don't intend to become vegan and I don't recommend it for my family. However, I do recommend to everyone that they get far away from the SAD (standard American diet), junk food, and excess meat consumption.
[1] - https://biology.stackexchange.com/questions/51664/what-makes...
Many of the most sustainable agricultural systems are 'permaculture' systems that combine animal and plant agriculture.
So far as health and diet, public enemy #1 in the standard American diet is junk carbohydrate. Junk fat is bad too but it is nowhere near as bad.
I'd like to do vegan, but the wife doesn't completely support it. She likes her cheese too much, and persuading her of the health benefits... well, I pick my battles :) I am happy that my routine work breakfast and lunch are plant based though! Between Thug Kitchen and other resources, I'm making progress in cooking food that's good enough that she won't miss cheese, meat, et al.
Obama's presidential cook, Sam Kass, wrote a good book (1) about simple things to help you eat healthier. The battle is won and lost in the grocery store!
(1) https://www.penguinrandomhouse.com/books/538595/eat-a-little...
ive had people tell me that dairy, sugar, smoking and any number of other things i consume on an incredibly regular basis are terrible for me "they ruin your body and mind" they tell me, however these same people often speak of my intelligence so either its not really as bad as all that or i was some sort of super genius and the only reason i havent cracked fusion yet is due to the amount of cheese i eat and having 2 sugars in my brew
sorry world but im not giving up my dairy so theres going to be no cure for cancer this christmas
I eat loads cheese and yogurt, wash it down with whole milk, and feel like a million bucks.
Then I try somebody's bean and tofu nonsense, and within an hour or so, I deeply regret it.
This is not meant as general advice though. For most of us, discovering the interactions of food and our own genetics is a life-long effort.