Yes, I am very familiar with this problem.
I am allergic to so many different foods that it's impossible to avoid them all without starving to death. In some cases, avoiding a certain allergen will decrease sensitivity and it can be reintroduced at a later date.
I didn't lose weight on the rotation diet because it was simply impossible for me to implement it given the sheer number of items I tested positive to -- my husband (who is a physician) was shocked when the results came. Prior to that, I suspect he was beginning to secretly believe I was a hypochondriac because I was constantly telling him I was ill -- no wonder! Every day I was taking in things that were incompatible with my body.
I had the ALCAT series done -- and I try to avoid the major offenders. But when you test positive to all of the ten most common preservatives in foods -- not to mention dairy products, wheat, and a ton of other things (including chlorine that is in our city water) -- that doesn't leave you with much to eat or drink.
But there is a book on this subject called, "Your hidden Food Allergies are Making You Fat". The authors are Rudy Fivera, MD and Roger D. Deutsch.
I can't say the program did anything for me because I am allergic to almost everything. But I could see it succeeding for those who might test in positive to a few offending substances.
Hope this helps.
"When you get into a tight place and everything goes against you until it seems you cannot hold on a minute longer, never give up then, for that is just the place and time the tide will turn. Success is endurance for one moment more." -- Harriet Beecher Stowe