I could write a novel on this topic, but unfortunately it is all non-fiction!
It started for me with migraine triggers - caffeine, chocolate, cheddar (white and orange), other orange cheeses, certain food dyes. I can have little bits every so often but too much will result in horrible headaches. I can't use most of the migraine medications because they contain caffeine. I can't even have decaffeinated coffee or tea as there are trace elements.
Then my stomach problems started and I had to give up wheat/gluten, though it has since been discovered that this isn't as big a problem.
Then in November I went to a naturopath who correctly diagnosed that many of my symptoms are from a candida allergy and I am on my second try of the diet to clear my system. I can't have ANYTHING remotely related to sugar including fruit (all forms), no vinegar or products containing it, no pork or beef (though I have a hard time with this one), and on and on.
To answer the question, yes I miss everything because there is so little I can eat at the moment, though if I can successfully get through this stage this time I will be able to slowly add things back. I am on several natural supplements, but that is not the same as a bowl of ice cream or a toasted salami sandwich with a couple of deli pickles!
But the first time I tried the diet, I started to feel so much better and started to lose weight. My pain levels were better and I was emotionally stronger as well.