Enjoy a variety of real food, primarily plants.Each word is important. She emphasizes enjoyment (taking time to savor your food and also learning to enjoy cooking as well as, e.g., shopping at the farmer's market), variety (not eating the same things over and over again), "realness" (staying away from processed foods), and a plant-based diet.
There is one recipe in the book, for beets, but she does give a little bit of advice, like that if you find vegetables too bitter, roasting them often brings out their sweetness. (Apparently sour tastes like lemon juice also decrease the perception of bitterness. I hate sour and don't seem to taste bitter very strongly, so I'm going to promptly ignore that advice.)
The book has a lot of encouragement that you can change your tastes, and I have found this to be true when I've tried it. If you lay off processed, overly salty and sweet foods for a while, you do learn to appreciate "normal" food more. It's a slightly difficult road to go down, though, at least for me, and the road in the other direction is quite easy. (Taco Bell might taste like crap the first couple of times but then it's delicious! And so easy! And cheap!)
Along with her emphasis that diets don't work ("even if you don't call it a diet!"), Bacon doesn't suggest that you forbid yourself any particular foods. For things that are comparatively energy dense or unhealthy, she suggests monitoring yourself for the point at which pleasure starts to drop off, and listening to that signal, and seeing if you've maybe had enough at that point. And I have found (independent of reading this book) that while I could eat several Twix bars or something, I can also keep a large bar of really good chocolate in my living room and eat very small amounts of it.
The book argues, as I've seen argued elsewhere, that Americans' obsession with protein is misplaced - that we all get plenty and most of us get far more than is necessary. A vegetarian diet is definitely not necessary for health, but a normal vegetarian diet with a variety of foods (not one dominated by sweets) provides plenty of protein.
Honestly, I can never figure out who is right on this protein issue, possibly because I haven't done any real research myself. According to the standard (government-sanctioned?) information about how much protein I should get, it's not automatic that I would get that much from a healthy diet. But that number may be something like enough protein for 98% of people my size (a population that includes men my size who have a lot more muscle), and I don't know what the curve looks like. For that matter, I have no idea how "how much protein X person needs" is calculated in the first place. What are the signs of protein deficiency/sufficiency?
Bacon advises getting some protein and some fat in every meal, for satiety and because (she claims) fat increases nutrient absorption. (She cites studies to this effect, I just haven't looked at them.) She generally advocates not being afraid of fat and not worrying too much about it, but substituting plant for animal fats where possible.
And as I mentioned above, she really does advocate enjoying eating. Her suggestions include not eating while distracted by other things (hard for me; I have a seriously ingrained habit of watching TV while I eat), eating family dinners together, and eating foods that you enjoy (while hopefully training yourself to enjoy more natural, home-cooked foods).
I think that's about as good a summary as I can give about this aspect of the book. I still recommend reading it; it's a pretty easy read in any case.