When it comes to eating, we can sometimes get lost in the myriad of self-mandates that govern precisely which food (or drink) we are putting into our mouth at that time.
Whether we are carb loading, on a high-fat low-carb diet, are paleo, are vegan, are in ketosis, are eating for sports performance, to put on muscle, to get lean, to look good in jeans, to impact thyroid function, to impact brain function, to help digestion… to do almost anything, the choice is so complex we may end up with analysis paralysis.
I narrowed the whole thing down to one simple principle. What does science say is the best all round diet for optimal health? And, without a shadow of a doubt, the best book, without narrative or agenda, that gets closest to this principle is the Perfect Health Diet by Paul and Shou-Ching Jaminet (both Ph.Ds). I heartily recommend.