I've realized that my joint pain and acne are probably due to leaky gut, exacerbated by a gluten intolerance. I stopped eating all grains a couple of weeks ago (had been 80/20 before, occasionally cheating with wheat before realizing what it was doing to me) and since then I've noticed that I seem to be sensitive to some other foods as well, including eggs and nuts (upset stomach, pain in knees and wrists, some breakouts).
I've decided to do an elimination diet to sort this out. According to what I've read, the common culprits for leaky gut are wheat, dairy, eggs, nuts and nightshades -- which I will avoid. I'm planning a diet restricted to grass-fed beef and buffalo, bone broth, sauerkraut, fish, oysters, coconut oil, and vegetables (including winter squash and yams as I seem to tolerate them). But I'm wondering if I could also eat fruit regularly, like 1 or 2 pieces a day. I can't imagine why I couldn't (I haven't read that fruit is commonly implicated in leaky gut) but I have noticed that most autoimmune diets = meat + vegetables, and do not seem to include fruit. Why is this? Should I avoid fruit to heal my gut, and if so, why? I don't need to lose weight.
In my early months of this lifestyle, I didn't fully realize my long list of health complaints were in fact autoimmune symptoms. I'm not sure why the diets you've checked don't include fruit but, right or wrong, I eat it. Others will know the potential problem, I'm sure, so you can make an informed decision.
I did avoid fruit for my first 3 weeks without grains. I didn't realize at the time that wheat was my problem. Once I gave up wheat I immediately began to thrive and that's still true. My favorite fruit happens to be grapefruit and since I don't take any meds I eat one nearly every day--a whole one, peeled.
After 3 weeks, I added grapefruit and all the popular fruits and many new vegetables and have had no trouble with any of them except brussels sprouts, which must be thoroughly cooked for me to tolerate them.
So, I can tell you that with my particular brand of autoimmune issues fruit is fine as long as you have an overall energy balance (for weight maintenance) or slight deficit (for gradual fat loss.)
From what I've read it seems that you can possibly become intolerant to anything when you have leaky gut, if your body creates antibodies against it. I think it happens more with specific proteins, though. I bet they leave off fruit because most people are in it for weight loss. I would warn against too much fruit, though, since sugar is highly correlated to breakouts in most cases.
I also recommend not reintroducing dairy at all. I didn't see signs of trouble until several months after I introduced heavy cream into my diet.
I would guess that what one must avoid depends on what categories of foods, and which particular foods within each category, triggers symptoms, or exacerbates underlying problems.
I rarely eat fruit, and then just a section or two of grapefruit, or a bit of lemon juice, or a couple of berries. What helps me doesn't necessarily mean it would help someone else, though. I find I feel better without fruit, with those rare exceptions.
Have you considered following a low FODMAP food plan?
I posted several links to information on the low FODMAPs diet here:
Also, do you avoid nightshades? Many have found that avoiding them helps.
I avoid FODMAPs, nightshades, oxalates, goitrogens, and high salicylates (except for tea.) With these parameters, my bones are much happier. :)
The FailSafe diet might also be helpful in pinpointing what causes trouble.
All the best to you. :)
If you have leaky gut or autoimmune issues, I can't recommend GAPS enough. I have systemic lupus, and it's put it into and kept it in remission. GAPS includes fruit once you get past the introduction, they have this to say about it:
Fruit should be eaten on their own, not with meals, as they have a very different digestion pattern and can make the work harder for the stomach. Fruit should be given as a snack between meals.
I don't do well on all types of fruit. I have issues with apples, bananas, and berries. I do well on melon, pears, and grapes. That's all I've experimented with, anyway.