If you suspect a food allergy or severe food intolerance, be sure to talk with your doctor, first and foremost. He or she will guide you in the step-by-step process of eliminating foods from your diet and reintroducing them to figure out what's causing problems.
According to foodallergy.org, an elimination diet usually lasts two to four weeks. Completely avoid the suspected foods during this time while your doctor or allergist keeps an eye on your symptoms. If one of these foods is causing an allergy, your symptoms should disappear by the end of this trial period.
The best elimination diets, according to precisionnutrition.com, start with taking away the largest number of foods. The more restrictive, the better. A few common culprits include dairy, gluten, peanuts, eggs, shellfish, tree nuts and citrus.
During this process, stick to foods like these:
-- Fresh fruit
-- Raw, steamed, sautéed or roasted vegetables
-- Nuts and seeds
-- Meats like fish and turkey
-- Rice milk or coconut milk
Your doctor might have you slowly reintroduce a problem food to your diet. If symptoms return, this food may be the culprit.
Keep a journal of how you're feeling during this process. Log your physical, emotional or mental signs and symptoms when eating these foods. If you're feeling better (more energized, sleeping better, fewer stomachaches, etc.) during the "elimination" phase, it's likely those foods have been causing issues for you.
Negative reactions to a food might include headaches, GI pain, fatigue, breakouts or rashes, bloating or brain fog.
Note: It's important not to try this without first consulting a professional — doctor, allergist or nutritionist — to be your guide along the way.