Elimination Diet: Reintroducing Challenge Foods

Elimination Diet Challenge Foods

Note: This is the second post in a two-part series about the elimination diet.  My guide to starting the elimination diet explains the first three to four weeks of the program, in which you’re completely eliminating a number of foods from your diet.  This post covers the reintroduction of “challenge foods” in the weeks following the initial elimination.

After several weeks of super clean eating, you’ll likely be more than ready to incorporate some more foods back into your diet.  By slowly adding food groups — also called “challenge foods” here — back into your diet one by one, you’ll be able to test for any sensitivities.

It can be incredibly tempting to stop following the plan at this point.  You’ll likely be feeling great and craving a BUNCH of different foods at once.  But chances are you’ve worked hard to get to where you’re at, and now you have the opportunity to pinpoint exactly which foods cause you to feel crummy.

So I’m here to tell you, YOU CAN DO IT!  Here’s how.

How do I reintroduce challenge foods after the elimination diet?

Each challenge food requires a four day reintroduction period.  You’ll eat a generous amount of your first challenge food (two to three average portion sizes) for the first two days.  For the next two days, do not eat the challenge food at all.  Throughout the entire four days, write down any symptoms you experience.  If you have no reaction to the food during this four-day period, keep it in your diet and reintroduce the next food using the same process — two days of eating the challenge food & observing, followed by two days of not eating the challenge food and observing.

If you experience ANY of the below symptoms, stop eating the food immediately.  Once the symptoms have completely cleared up, you can move onto the next food.  Keep in mind you’ll be able to return to any problem foods and retest them once you’ve reintroduced the remaining challenge foods (more on this in a bit).

  • Diarrhea
  • Constipation
  • Fatigue
  • Depression
  • Anxiety
  • Gas/bloating
  • Abdominal pain
  • Headache
  • Muscle or joint pain
  • Skin irritations/breakouts
  • Nasal/chest congestion
  • Major changes in kidney/bladder function
  • Major changes in energy level

If you do NOT experience any symptoms after not eating the food, followed by a 48-hour observation period, reintroduce the next food.

Does the order in which I add challenge foods back in matter?

Studies have shown that the order in which you add back foods doesn’t seem to be critical.  Begin with whichever food you’ve been craving the most while on the elimination diet!  I’d recommend prioritizing the order for how you’d like to reintroduce them.

You’ll want to test pure forms of each challenge food — in other words, they shouldn’t have additives or other ingredients you’ve been eliminating.  Here’s a chart detailing sample foods from each challenge food group, along with recommended portion sizes for reintroduction.

Group
Challenge Food
Average Portion Size
Barley, Rye Cooked barley, rye cereal,
rye crackers
1/3 cup,
3 oz.
Citrus Oranges,
orange juice
1 medium orange,
8 oz. juice
Corn Fresh or frozen corn kernels 1/2 cup, 1 small cob
Dairy Milk (skin, 1%, 2%, or whole milk),
any whole milk cheese with no additives
1 cup,
1 oz.
Eggs Egg whites, scrambled; egg yolks, scrambled 1 egg white, 1 egg yolk
Nightshades Tomatoes, potatoes, peppers, eggplant, goji 1 small or 1/2 cup
Peanuts Raw or dry roasted peanuts,
peanut butter made of 100% peanuts only
1/4 cup
1 tablespoon
Soy Edamame,
soy milk,
tofu, tempeh
1/2 cup,
1 cup,
1/2 cup
Wheat/Gluten 100% whole wheat cereal or 100% whole wheat noodles 1 cup
Caffeine Green tea, black tea, coffee 1 cup
Refined Sugars Chocolate, etc. 1 oz.

I had a reaction to something.  Now what?

You can retest any challenge foods that cause symptoms using the same four-day process.  If you show symptoms again, it’s recommended that you remove the food from your diet for three to six months.  It’s also recommended that you check in with your doctor, as there may be other foods or dietary supplements to help promote intestinal health.

After you’ve completed the initial testing of all the foods that you removed during the elimination diet, you can further test for nuances of sensitivity within a single food grouping.  It may be that certain foods cause symptoms, but other foods in that group can be tolerated.  I found this to be the case with dairy — I had a severe reaction to milk, but was able to eat cheese without any problems.

And one big caveat to all of this?  It’s always good to keep in touch with your doctor about any major changes you’re making to your diet.  He/she will likely have some great recommendations to help you along the way!

What’s next?

The fun stuff!  Now that I’ve shared the basics about the elimination diet and how to reintroduce challenge foods, I’ll be sharing menu ideas, grocery lists, and recipes for healthy, clean eating — many of which will be elimination diet-friendly recipes, like the below slow-cooked lamb with wild rice and roasted butternut squash.  Check back soon!