Found on www.lifehacker.com, written by Dr. Amy Shah. A helpful article about food intolerance and how to narrow it down. "How To Find Out Which Foods Are Making You Sick [caption id="attachment_1361" align="alignnone" width="300"] Image remixed from ayelet-keshet (Shutterstock) and moonkin (Shutterstock)[/caption] Although food allergies are still rare (affecting about five percent of the population), food intolerances are quite common. I see patients for food intolerances every day with symptoms like constipation, difficulty swallowing, heart burn, bloating, and headaches. But how do you figure out which foods might be affecting you? For many allergic and food intolerance issues, I ask patients to go on a food restriction diet ranging from one week to one month. After following this plan, many of them experience weight loss, fewer menopausal or PMS symptoms, a decrease in acid reflux, better energy, better sleep, a clearer complexion, and more. Even I was surprised at first. After seeing so many of my patients experiencing these positive side effects, I decided to try it myself. One month later, I concluded that I was going to take out some of these foods for good because I was feeling so fantastic. It's important to note, however, that food allergies and food intolerances are two very different things. Food Allergy vs. Food Intolerance A food allergy is an immediate immune reaction usually resulting in throat tightening, hives, and even anaphylaxis. Even a microscopic amount can elicit a life-threatening reaction. If you think you have a food allergy, consult a doctor and do not try to diagnose yourself. A food intolerance is usually a delayed reaction that can cause intestinal issues or other symptoms. This is an area where much research is being conducted about the immune system and other mechanisms. In fact, we are finding more and more conditions that are affected by the food we eat. So, in short, these food intolerances can be causing all kinds of symptoms that range from headaches to bloating. To figure out what food intolerances you may have, I have an eight step food elimination plan that you can do yourself. This is really is the gold standard—even better than those expensive blood tests. In fact, blood testing for food intolerances is not FDA approved and research on any type of food intolerance blood testing is controversial at best. Remember, because these foods the most common culprits, the FDA requires labeling of these food groups by all manufacturers. Therefore, except for corn and additives, you will always be able to read labels to identify hidden sources of these foods. Try to stay off dairy, wheat, soy and eggs for 2-3 weeks. This includes yogurt, cheese, whey, and processed foods with eggs as an ingredient. Add them back one item at a time separated by 3 days. Then, remove peanuts, shellfish, corn for 2-3 weeks. Remember to read labels and ask for ingredients at restaurants. Add them back one item at a time separated by 3 days. Remove tree nuts (i.e. almonds, walnuts, cashews), and all fish for 2-3 weeks. Add them back one item at a time separated by 3 days. Eliminate any foods or drinks with preservatives such as MSG, artificial sugars, and artificial dyes for 1 week. This is probably the hardest part because it includes sodas, most alcoholic drinks, and snacks, but it's only a week! Add back each (if you want) separated by 3 days. Now you are done! You should permanently remove the foods that caused your symptoms such as bloating, joint pain or swelling, brain fog, or constipation. The theory behind this plan is that certain foods cause inflammation of the intestines, joints, or stomach. Now if you add the offending food back, you will notice that your symptoms are back, sometimes with a vengeance! Usually, I find that it takes at least 2 weeks to notice any difference in your symptoms. That's way we try avoidance for 2-3 weeks. In fact, the longer you do avoidance the better the results. Food additives and preservatives usually don't even take that long. If you think you may have a life threatening allergy or you are still confused, visit a board certified allergist immediately. But if you are able to identify your food triggers that cause uncomfortable issues, your body with thank you."