However, I disagree with this premise frankly. A lot of the studies which led to these classifications are poor quality, backwards looking, and rely upon people remembering what they ate for the last quarter. Nutrition research is poor for a variety of reasons, sadly, and who hasn’t experienced the seasons of change with one article one day claiming eggs/coffee/wine/whatever are bad one season and the next that they are good and then bad and then good and then…
I’ve taken this up as a hobby, in my studies I have found an extremely wide and deep base of people who point out a dramatic improvement in their mental and/or physical health by cutting out plant matter. Many times these people have had chronic, difficult, conditions and had been told it was incurable.
Personally, I don’t believe vegetables are necessary. I am not a zealot however (just made a bluecheese steak salad for the family) and I think nuance is key here. We’ve all been told to eat the rainbow, vegetables are good, meat is bad, etc. However I think that it should be an individual decision, some don’t do well with vegetables high in oxolates, or lechtins, or glycoalkaloids. I LOVE spicy food [and nicotine] as in nightshades, (thanks to adhd?) and while I think I would do better without it I still eat them. I also think if you are eating highly processed meats like charred burgers or smoked salami with beer and bread and condiments that isn’t great and will lead to shortened life span.
I don’t want to drone on, my point is there is a lot of nuance and individual variability. Also, strict diets tend to cut out ultra processed foods (vegan to carnivore). We should not simply assume that all vegetables are good for all people. Some veggies are better than others. Some people process things differently. Healthy meats are healthy.
For anyone interested in further reading look up: https://www.diagnosisdiet.com/
https://www.amazon.com/Brain-Energy-Revolutionary-Understand...
More on the “carnivore” diet fringe-y side:
Paul Saladino
Shawn Baker podcast for testimonials
Anthony Chaffee
In summary, there is a lot we don’t know but it appears that people eating an alternative diet are doing great. We shouldn’t just discount that because of “settled science.”
For me, by far the most interesting development in mental health is Chris Palmer's work, which asserts that most mental illness is primarily a metabolic issue. If you think that can't be possible, read his 2022 book[1]. Here's a podcast[2].
[0] https://www.nature.com/articles/d41586-022-02871-w [1] https://www.amazon.com/Brain-Energy-Revolutionary-Understand... [2] https://www.youtube.com/watch?v=oC-sQogfh3Q
Not sure how much evidence is for claims, but sounds somewhat reasonable.