Best way to find out is to leave it out for a few days.
Or try this:
Take a drop of the food in question (if the food is solid, mash and mix with a bit of water) and place it on the inside of the wrist of the patient. Do it at bedtime. Let the drop dry on the skin, then let your patient go to sleep. In the morning check the spot: if there is an angry red reaction, then avoid that food for a few weeks, and then try again. If there is no reaction, then go ahead and introduce it gradually starting from a small amount.
I hope the link is clickable. Otherwise go to gapsdiet.com and find Introduction diet.
Post Edited (Andrina) : 12/26/2012 1:27:16 AM (GMT-7)