I did paleo on the suggestion of a doctor and a nutritionist. Better to start with, then no difference. I am gluten/diary free anyway now, after testing, and the discovery when I tried to put them back in, they made my stomach hurt and my eyes red and itchy. Overall, paleo was not helpful to me - too much protein in the way it was advised. I have a kidney condition that makes that undesirable. I then did McDougall on the advice of another doc (on the grounds that fats feed protomyxzoa). No difference really, other than poor blood sugar control - which had improved with paleo. I tried metabolic typing, no difference. I then had a prolonged sulk with the diet thing, and ate crap. Now I am trying to find the balance, and eat fresh, healthy foods, exclude the ones that make me worse (most of the time) relatively low fat (it looks like my genetics may predispose me to cancer) organic when I can get it, lots of fresh green leafy veg, and TRYING not to be sugar's bitch. Blood sugar issues are intimately bound up with this disease for me.
One thing I would say - if I now observed every dietary taboo that has been suggested to me, in terms of oxlates, sulphates, carbs, proteins, fats, I would starve to death. And taking stuff out is much easier than trying to put it back in. My doc said to me she reckoned most people benefitted from dietary change - any change (other than pure rubbish I guess) because it gives the gut a break from whatever its got pissed off with. But unless you are eating something that gives you what you need to thrive, that benefit is unlikely to last.