Perfect Health Diet (https://www.amazon.com/Perfect-Health-Diet-Regain-Weight/dp/...), despite the very unscientific name, it's the result of the work of two scientists into optimizing their diet for better health. It walks through what's essential in a human diet (micro-, macro nutrients), and also compares to the diet of various traditional tribes, other mammals. The book documents a clear cause-and-effect network between many nutritional issues and the resulting diseases. I learnt a lot about the mammal metabolism from this book.
The most significant factor arguing for this book is that almost every assertion is supported by a multitude of significant studies.
Some quick takeaways:
* dose makes the poison: for almost every nutrient the body needs, there's a certain interval in which that nutrient is beneficial, above which that nutrient is toxic. (yes, this may seem tautologically true, but it's important)
* the diet of the ancestral man, and most wild mammals is strongly based on saturated and mono-unsaturated fats. This is in strong contrast with the modern American diet, which is strongly based on carbohydrates. As the book carries on the explain, those fats are the exception to the above takeaway, those two types of fat pass through the organism with very little stress to organs, it's a simple reaction which results in no toxic by-products.
* there are some commonly consumed things which are actively harmful and are associated with a range of diseases. Some of those are grains.
(anyway, it's been some time since I've read it, I do recommend it as a very well thought out book on nutrition for those interested.)