How to keep your energy up when trying an elimination diet, according to doctors

If you suspect that you have some kind of food allergy or intolerance, there’s one thing that basically every doctor will recommend: an elimination diet. The whole process of nixing popular irritants such as eggs, dairy, gluten, corn, soy, sugar, alcohol, coffee, and nightshades (phew!) and slowly adding them back in one at a time is one of the few widely-accepted methods to determine food-related issues. And it often comes with a major unwanted side effect: fatigue.

“An elimination diet is a short-term eating plan with the goal of pinpointing exactly which foods are causing the uncomfortable, painful, or mysterious reactions you are experiencing that could be the result of an undiagnosed food sensitivity,” explains Amy Myers, MD, a functional medicine doctor and author of The Thyroid Connection. “This is not a life-long diet; it’s a strategy to help you uncover which foods you should avoid and which you can enjoy.” Meaning that low-energy feeling as you nix certain food groups should be temporary, not a constant companion.

However, considering that Dr. Meyers says the whole elimination diet process can take three to six weeks, that’s quite a long time to feel sluggish and low-energy. So if your doctor recommends that you go on an elimination diet, how do you pull it off without feeling drained?

“Normally, people shouldn’t feel tired when doing an elimination diet,” says integrative and functional medicine doctor Sommer White, MD. But she adds that there are a few common mistakes many people make when doing an elimination diet that can make them feel like they’re running on empty. Here, she, along with other leading medical experts, explain what exactly many do wrong—and share how to do it the right way, so you’ll feel energized all the way through.

Keep reading for tips on how to do an elimination diet without feeling totally depleted.

1. Replace, don’t restrict

“One problem right off the bat is that when people hear ‘elimination diet,’ they think of restriction,” says Aviva Romm, MD, author of The Adrenal Thyroid Revolution. She explains that while, yes, there is a list of foods you’re taking out of your diet, you shouldn’t be eating less food overall. “Elimination diets are more accurately replacement diets,” says Dr. Romm.

She says that while you’re taking some foods off the table, you should be adding more fiber, proteins, and healthy fats to your plate—all of which give energy. “This requires thinking about how you’re getting enough protein and healthy fats,” she says. In the healthy fats department, Dr. Romm says olive oil, avocado, and coconut butter are usually all okay to eat on most elimination plans. As for protein, if you’re eliminating eggs and nuts as part of your diet, she suggests incorporating more seed butters (like sunflower seed butter) into your meals. It’s essential to talk to your doctor or dietitian for specific suggestions that work on your unique eating plan, since elimination diets vary from person to person.

Dr. White says that she also notices people in this position are also battling a fear of food, which can make them eat less while on an elimination diet. “I’ve definitely had patients who are scared to eat virtually anything because it could cause a bad reaction,” she says. If this is true for you, Dr. Romm advises focusing on how you’re on a mission to heal your body, not restrict. “Get really curious about your body and think of it as a way to figure out what’s going to give you the best energy and be healing,” she says.

2. Know the first five days may be rough

All three doctors say that one major reason why many people feel tired when doing an elimination diet is because they’ve been relying on sugar and carbs for quick energy and once they cut them out, they realize how their body runs without these foods—and it isn’t pretty. “I call these foods ‘false fires’ because they give you a false sense of energy,” says Dr. White. “You don’t really see what’s underneath that false fire until you remove them and then you can really see what your real level of energy is.”

Dr. Romm says these symptoms only last about five days, and once you get through that hump, you’ll find that you actually have better energy than before because your body is relying on whole grains, fiber, protein, and healthy fats, and not sugar and carbs. If you’ve ever heard of someone starting a new diet and say they felt like they had the “flu” the first few days and then felt amazing a few days after, that’s similar to what can happen here.

When getting through this initial hump, the experts again reiterate that relying on fiber, proteins, and healthy fats for energy is key. Dr. White says whatever you do, don’t “cheat” and eat a food that’s not on your approved eating list—because you’ll have to start all over. If you’re still feeling tired and slow after this hump period, you should check in with your specialist to reevaluate the plan and make sure you’re getting enough of the right nutrients.

3. Keep your other healthy habits front of mind

If you haven’t been drinking enough water or getting enough sleep, Dr. Romm says an elimination diet is going to make that even more obvious because you likely won’t be able to rely on foods with caffeine or sugar to get through the day. But again, she says the payoff will be worth it. So now is definitely the time to make sure that you’re actually going to bed at a decent hour, getting enough physical activity, and drinking plenty of water (along with other essential wellness practices).

“Embarking on an elimination diet is an enlightening and empowering process,” says Dr. Myers. “Your body knows best. Listen and pay attention to it. By doing an elimination diet, you can take charge of your health, and make changes exactly as your body is asking for it.”

Here are some signs that your clean-eating mindset has morphed into something unhealthy. Also, see how at-home gut tests can help clue you in on foods that are causing problems for your body.