While it’s not 100% fool-proof, an easy way to test for a intolerance is to take note of what foods you are eating and how they make you feel afterward. Then eliminate the food from your diet entirely for 21 days. This is called an Elimination Diet.
For example, if you want to test whether you are intolerant to dairy, you would eliminate all dairy from your diet. This means more than just not drinking milk with cookies. No dairy of any kind. No cheese, no ice-cream, no whey protein shakes – total elimination. After three weeks see how you feel.
If you feel better, you can fairly safely say that you are intolerant to the food you eliminated. (Note that you should always also seek a full evaluation from a physician as well to rule out any other health issues.)
If you do not feel better, you are basically at square one with no ability to make a conclusion as to whether this is a food you are intolerant to. There are a few reasons for this. Here is a list of possible reasons why you may get a false negative result from an elimination diet:
- Three weeks might not be a long enough time for you to feel results.
- You may have intolerance when particular foods are combined in your system and not merely eaten alone.
- You could have so much internal damage from eating foods you are intolerant to for so long that the healing is not possible in that short a period or, depending on your age and level of damage, ever.
- You may have consumed small or trace amounts of the food during your elimination diet thus causing your results to be inaccurate.
- You may very well be intolerant to a food but have other physiological issues going on that are overriding any improvement you may otherwise feel from eliminating the food.
Note also, that you may feel great after an elimination diet concluding you are intolerant to a particular food only to slowly but surely feel badly again several weeks or months later. Most people with food intolerances have an intolerance to more than just one food. So, when testing through an elimination diet it can be tricky to determine exactly which foods you are intolerant to.