Michael doesn’t advocate veganism because traditional diets, the gold standard he uses, include meat, fish and dairy.
The book’s goal is to help lay people eat healthily, if you want scientific evidence check out his other books. That said, the author warns that we still know very little about nutrition, hence the book’s focus on low-contention ideas backed by significant evidence of lower mortality and disease rates.
How did I grow from this?
It’s been five years and I still regularly check ingredients labels and apply many of these rules like mixing colors or not eating food-like edible substances with too many ingredients that a child can’t pronounce. Even though I still struggle to apply the core three rules consistently, I feel like I’m directionally correct and healthier thanks to the author.
I had read some of these rules before in different contexts but they didn’t transfer into action. I think what made it for me was the focus on simplicity, execution, and grand-mother-style advice.
The author seeks the truth in an area where we don’t know much because of how complex the human body is. The mental model I see under most of these rules is evolution: eat what our bodies evolved to eat and eat the way we used to eat.
In Antifragile, Nassim Taleb advocates fasting based on our hunter-gatherer past. There is also a mounting body of evidence suggesting that caloric restriction in the form of traditional long-day or multi-day fasting or, more sustainably, intermittent fasting, increases lifespan. On the same topic of fasting, Ayurveda recommends different levels of fasting depending on your personal constitution (vatta=movement, pitta=fire, kapha=water).
Another idea that comes to mind is Taleb’s recommendation to be very careful when modifying a complex systems like the human body because actions can easily result in non-linear effects.