Have you already been acquainted to Wallace Wattles' "The Science of Being Well", published in 1910? I just finished reading it and I find it somehow speaking to me. Most of what the author is talking about is easy to understand, sticks to your mind and is also a nice change and addition to all the east-influenced spiritual or modern scientific approaches I've found myself surrounded with so far when it comes to health and nutrition.
First half of "The Science of Being Well" deals with the author's philosophical and theological approach to being well, while in the second half he focuses on what to eat, how to eat, when to eat, how much to eat and so on (plus later on appropriate breathing and sleeping). One must not agree with everything and keep in mind that science in Europe was at a completely other level back then but taken en masse, a lot of it makes sense, I believe.
Some of the quotes which I wrote down for myself: