Don't get too excited—unless you have a diagnosed condition like celiac, you're probably not going to get this tax break. Still, it poses an interesting question. What about people who have tested positive for food allergies or people diagnosed with Crohn's or IBS? You can write off medical expenses if they exceed a certain percentage of your income, so if eating a certain way is part of your treatment, why can't you write off those added expenses? Tell us what you think in the comments below!