Skipping out on certain foods in the name of weight loss is nothing new—but the latest trend in elimination diets has little, if anything, to do with weight loss. Now, throngs of health-conscious eaters are turning to elimination diets in an effort to cure everything from headaches and fatigue to skin irritations and digestive woes.

And while the average person probably doesn’t suffer from food intolerances, an elimination diet is the best way to identify any problems for those who might, says nutritionist Rania Batayneh, M.P.H., author of The One One One Diet.

Here’s how it works: You cut out the most common foods linked to intolerances—dairy, soy, nuts, eggs, gluten, sugar, and alcohol—for three to four weeks. "The goal of the elimination phase is to entirely remove the foods' antibodies from your body, which takes several weeks," says Batayneh. "Then, reintroduce one food at a time so that there's no confusion as to which food caused a bad reaction. Pay close attention to your body after the reintroduction of a food—not just immediately, but up to two days afterward—so that you can link symptoms to the food. If the reintroduced food didn't cause any adverse reaction, move on to the next possible culprit—and continue until you can identify the foods that are causing trouble."

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Problem is, the symptoms of food intolerance are anything but easy to pinpoint. For instance, the most common symptoms—fatigue, bloating, constipation, diarrhea, headaches, brain fog, rashes, joint pain, and inflammation—can all be blamed on anything from a bad night’s sleep to a too-hard workout.

And unless you really have a food intolerance, there's no health benefit associated with cutting out otherwise healthy food groups, such as dairy and gluten, says Batayneh. For instance, if you’re cutting out gluten, you could miss out on health-boosting whole grains. (Check out four gluten-free ways to get the nutritional benefits of whole grains.)

MORE: 6 Ways to Get More Calcium That Don't Involve Eating Dairy

If you do decide to try an elimination diet, planning is key. "Plan a shopping list so that your kitchen is stocked with alternatives," says Batayneh. That will help ensure that you get all of the nutrients your body needs—but none of the items that are on your list of now-forbidden foods. After all, even the tiniest little slip up can skew your results.

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