Well, I have to maintain a low-GI, moderately low-fat diet or I become physically unwell. I'm also lacking the enzyme needed to digest milk solids, so I have to be very careful about dairy foods (at home I always have lactose free skim milk on my museli or in my coffee, for example). I can't eat green capsicum (green bell pepper) at all, unless I want sharp pain in the abdomen and intestines for a few hours as it moves through my system. Oh, and I can't consume aspartame in any way, shape, or form (it triggers an episode of joint pain, headache, and fatigue, generally speaking).
None of this is really "spiritual" as people commonly think of it, but when your body is very loudly demanding your attention due to pain or bloating or other disturbances, it really has a way of making it difficult to focus on anything else, or so I find.
Our family aren't vegetarian, though I occasionally toy with the idea. We do eat vegetarian meals fairly regularly, and the emphasis of our diet is whole grain breads, whole grain pasta, fresh (or frozen) vegetables, fresh fruit, eggs, and dairy in moderation (cheese, yoghurt, milk, etc., though the milk is mostly for the kids or for cooking, aside from my morning museli, which is, in fact, organic). I like to make simple, straightforward meals that are balanced and not too high in fat (soup, pilaf, lentils and rice, that sort of thing), using meat mostly as just one of the ingredients rather than the main attraction (I admit we do sometimes have steak or a roast, but that's the exception rather than the rule). I wouldn't say our diet is especially organic, but we don't buy a lot of processed foods, certainly. Simple, basic, tasty food, with or without meat, that's what suits us best (and me, in particular, since I'm usually the one who cooks!).