Sounds like a good book. I've been sold on an "ancestral health" diet - in my case, a low-wheat take on the Weston A. Price Foundation principles - for about 4 years, and my health has improved drastically in that time. I've been able to stop taking asthma meds that I was on for about twenty years, and by avoiding processed carbs, have returned to my high-school weight after having 3 babies... not bad, compared to much of America, I think.
You might enjoy "Nutrition and Physical Degeneration" by Weston A. Price (available for free online if you google). It documents case studies of traditional people and their diets, then contrasts them with members of those societies that have switched to a Western diet. It was written in 1939, when the Western diet was not quite so prevalent around the world, and it is quite convincing. The reason I thought of it was that, aside from being a great resource, it shows over a dozen examples of
sustainable ways to eat traditional foods, from a Scottish village that ate mostly seafood and oats (homegrown, of course, not Quaker!), to a Swiss village that consumed mostly rye bread (properly sprouted/soured) and
dairy from pastured animals.
I do have to mention, once you get past the mass media's take on nutrition, and get into Ancestral Health/Traditional foods/Real food thinking (where much of the great research and thinking is taking place now!), many of the rebel-Paleo types like Chris Kresser and Paul Jaminet advocate eating a moderate amount of carbs, not an extreme-low-carb diet like the Atkins diet or some of the Paleo types. So, especially if you're expending plenty of energy building a
permaculture homestead, carbs aren't necessarily "out" as staples. Chris Kresser, Paul Jaminet, and Matt Stone in particular advocate potatoes, sweet potatoes, white rice, cassava, plantains, etc. as "safe starches" that don't wreak the same metabolic havoc as grains and processed carbs. Also, as it sounds like you are discovering, once you are free to embrace saturated fat from pastured animals as a cornerstone of your diet, you suddenly need far fewer grams of food to provide
enough calories for the day! Unless you're some kind of serious body-builder, a super-high protein diet probably isn't necessary, as a high-fat, moderate protein, lowish carb one seems easier to "grow yourself."
It seems like
permaculture is tailor-made for producing traditional foods. I guess your acreage, land type, and preferences would dictate your specific set-up, but a few
chickens for eggs and a maybe a dairy goat/cow for
milk and cheese seem sufficient for fat and protein. Omega-3's can come from both of these, and as long as Omega-6 levels are kept very low, it seems that these sources would be enough, without necessarily needing a fish source.