The GAPS diet —which stands for Gut and Psychology Syndrome — is designed to reduce inflammation and heal the gut.

It’s based on the theory that various inflammatory conditions stem from an unhealthy gut and by restoring gut health, you can rid the shackles of disease.

However, you may be curious about the details of the diet and whether it can work for you.

This article explains how the GAPS diet works and discusses its benefits and downsides so you can determine whether it’s right for you.

GAPS diet

What is the GAPS diet?

Gut and Psychology Syndrome (GAP Syndrome or GAPS) is a condition that establishes a connection between the digestive system and brain.

The term was coined in 2014 by Natasha Campbell-McBride, a neurologist.

She claims that an unhealthy gut causes various inflammatory, autoimmune, and digestive conditions, including:

She also links an unhealthy gut to bedwetting, eating disorders, schizophrenia, depression, bipolar disorder, ADHD, and autism.

Cambell-McBride claims that by healing and “sealing” a leaky gut, you can restore the bacterial ecosystem within the digestive tract and rebalance the immune system to cure these conditions.

She suggests you can do this with her GAPS diet, which involves dietary intervention, targeted supplementation, and detoxification methods.

GAPS diet protocol

The GAPS diet protocol involves two stages — an introduction phase and the full GAPS diet.

The GAPS introduction diet

The introduction stage is an elimination-style diet that consists of six stages and lasts 3–6 weeks.

It’s designed for patients with severe digestive and neurological conditions but Cambell-McBride explains that you can skip the introduction stage and start with the full GAPS diet.

In the introduction phase, foods low in fiber and that are easily digestible are slowly and progressively introduced throughout the six stages.

These foods include:

  • homemade stock or bone broth (gut healing)
  • quality protein (meat, fish, eggs)
  • vegetables
  • fermented dairy

The goal of this stage is to heal and seal the gut lining quickly.

Once you have a normal bowel movement, you can move to the full GAPS diet phase.

The full GAPS diet

After moving through the six stages of the introduction diet, you’re allowed to expand your food choices in the full GAPS diet stage according to a long list of allowed and prohibited foods.

If you skipped the introduction phase, Cambell-McBride recommends following a specific dairy introduction structure, which could take up to 18 months to complete.

The full GAPS diet is similar to the specific carbohydrate diet (SCD) and lasts until your symptoms resolve, which may take 1.5 and 2 years according to Cambell-McBride.

At least 85% of what you consume daily should consist of meats, fish, stocks or broths, eggs, fermented dairy, and vegetables.

As part of the GAPS diet protocol, Cambell-McBride recommends various supplements like probiotics and fish oil as well as detoxification methods, such as coffee enemas, swimming in natural waters of lakes, rivers, and seas, and avoiding man-made chemicals like new carpets and fresh paint.

GAPS diet food list

Here are the foods to eat and avoid on the full GAPS diet:

Foods to eat

  • Fruits: apples, apricots, avocados, bananas (ripe), berries (all kinds), cherries, grapefruit, grapes, kiwifruit, kumquats, prunes, tangerines
  • Vegetables: artichoke, asparagus, beets, bok choy, broccoli, brussels sprouts, cabbage, cucumber, kale, spinach
  • Poultry: chicken, eggs (free range), goose
  • Meats: beef, game, lamb
  • Seafood: anchovies, bass, cod, haddock, salmon, trout, walleye
  • Dairy: asiago cheese, blue cheese, butter, cheddar cheese, ghee (homemade), gouda cheese, swiss cheese, yogurt (homemade)
  • Nuts: almonds, Brazil nuts, hazelnuts, walnuts
  • Legumes: beans, dried white (navy)
  • Herbs, spices, and condiments: cayenne pepper, cinnamon, garlic, honey, spices (single)
  • Beverages: coffee (weak), gin or scotch (occasionally), ginger root, herbal teas, juices (freshly pressed), tomato juice

Foods to avoid

  • Fruits: canned or preserved fruit
  • Vegetables: canned or preserved vegetables, okra, potatoes (white or sweet)
  • Meats: bologna, ham, hot dogs, and other processed meats
  • Seafood: processed fish, predator fish, including shark, tuna, halibut, and mackerel
  • Dairy: acidophilus milk, buttermilk cheese (processed and cheese spreads), chevre cheese, cottage cheese, cow’s milk, cream, feta cheese, ice cream, margarine, rice or soy milk, sour cream, yogurt (commercial)
  • Legumes: baked beans, black-eye beans, cannellini beans, chickpeas
  • Grains: amaranth, barley, buckwheat, cereals, including all breakfast cereals, corn, couscous, millet, oats, quinoa, rice, rye, wheat
  • Condiments: balsamic vinegar, jams, jellies, ketchup
  • Additives: acesulfame, agar-agar, agave syrup, algae, arrowroot, aspartame, astragalus, baker’s yeast, baking powder, bee pollen, carrageenan, cellulose gum, cornstarch, corn syrup, dextrose, fructose, molasses, pectin, saccharin, sucrose,
  • Other: bouillon cubes, chewing gum, chocolate, vegetable cooking oils
  • Beverages: apple juice (commercially prepared), beer, brandy, coffee (instant), soda, tea (instant)

Sample GAPS diet menu

Here’s a sample of what one day of meals and snacks may look like on the full GAPS diet:

Breakfast:

  • mineral water
  • fresh pressed carrot juice
  • lemon and ginger tea
  • broth with meat and vegetables
  • slice of nut bread

Snack:

  • peeled apple

Lunch:

  • broth with meats and vegetables
  • 3 tsp of ripe avocado
  • scrambled eggs cooked with ghee or coconut oil
  • carrot sticks

Snack:

  • homemade yogurt

Dinner:

  • broth with meats and vegetables
  • grilled meat, sauerkraut, salad of carrot, tomato, onion, and cabbage
  • apple puree

Snack:

  • fresh pressed juice: carrot, mint, celery, mango, pineapple

Benefits

Cambell-McBride suggests that the diet heals the gut lining, restores a healthy gut microbiota, and rebalances the immune system.

There is evidence that certain dietary patterns like the Western or standard American diet (SAD) — which is rich in sugar, refined grains, and packaged convenience foods — are associated with dysbiosis and leaky gut (1).

Dysbiosis occurs when the health of your gut microbial community becomes imbalanced.

For example, the Western diet has been associated with many of the conditions for which the GAPS diet claims to cure like Crohn’s disease and ulcerative colitis (2).

And many foods allowed on the GAPS diet like fermented foods and certain fruits and vegetables have been shown to nourish good gut bacteria and decrease gut inflammation (3).

The GAPS diet also limits foods that negatively impact gut health, such as saturated fats from processed meats, snack foods, and fried foods, as well as refined grains and added sugars.

To this point, components of the GAPS diet may improve intestinal health, particularly in those who follow a Western-style diet.

As an elimination-style diet, the GAPS diet — particularly the GAPS introduction phase — may also be helpful for identifying foods or ingredients to which you may be sensitive or allergic.

Without following an elimination diet, it can be difficult to identify specific foods that may be contributing to your symptoms.

At the same time, though, it may also lead to unnecessary food restrictions.

Downsides

If you’re considering trying the GAPS diet, here are some downsides to keep in mind.

False promises

The GAPS diet is centered around foods that heal a leaky gut, which Cambell-McBride cites as the cause of many diseases.

Leaky gut occurs when the gut lining becomes compromised and allows bacteria and harmful substances to pass from the intestines to parts of the body like the brain where they can cause inflammation and health problems.

While once a term used by alternative health practitioners, it’s becoming increasingly clear that leaky gut is real and contributes to various diseases.

However, it’s unlikely that leaky gut directly causes these conditions as Cambell-McBride suggests, but instead contributes to them in susceptible individuals (4).

So to claim that following the GAPS diet can cure conditions — many of which have no known cure — can be damaging in that it leads to false hope and expectations by vulnerable people who are willing to try anything to cure their or a loved one’s condition.

Certainly, components of the GAPS diet may improve the symptoms of some conditions, but it is certainly no cure, especially in the absence of published evidence.

As a medical practitioner, Cambell-McBride is well aware of the scientific rigor that goes into developing and conducting studies and the importance of publishing findings to inform other researchers and the public about what works and what doesn’t.

And because Cambell-McBride claims to have successfully treated thousands of patients with the GAPS diet, she has no shortage of patients to publish her findings in a peer-reviewed journal.

The fact that she hasn’t, further suggests that her claims to cure disease are clearly overreaching and largely false.

Also consider that if people claim the GAPS diet cured a condition like autism, they may not have had that condition in the first place.

Difficult to follow

Any type of elimination diet is difficult to follow — and follow correctly — with no exception for the GAPS diet.

The long list of foods to avoid along with the other rigid rules for detoxing and supplementation is anything but manageable for most people.

Those who have tried countless treatments in the past to cure or reduce their digestive or inflammatory symptoms may be more motivated to stick with something like the GAPS diet, but that motivation can quickly wane with time, especially in the absence of symptom relief.

Cambell-McBride does offer a lot of support through her website, books, videos, and so-called certified GAPS practitioners — who, by the way, require no formal medical or nutrition education — but even these resources may not be enough to stick with the diet long-term.

The GAPS diet can also become expensive quickly and is time-consuming since you have to make most of your own foods like broth, yogurt, or condiments like ketchup and mayonnaise, further adding to the challenges in following the diet.

Should you try it?

The GAPS diet remains popular among those with chronic inflammatory conditions looking to treat their symptoms.

While components of the diet can support gut health and therefore reduce inflammation that may help alleviate certain symptoms, there is no evidence to support the GAPS diet for the conditions it claims to treat.

As an elimination-style diet, the GAPS diet may help you identify foods linked with your symptoms, but it can also lead to other unnecessary food restrictions that can not only impact your health but the quality of your life.

Still, elimination diets are difficult to follow correctly, and certified GAPS practitioners likely don’t have the competencies or credentials to provide adequate support.

Even then, most states in America require licensure to provide nutrition therapy for the conditions that the GAPS diet claims to treat, so those without licensure who are administering the GAPS diet are doing so illegally.

In either case, reducing the amount of processed foods in our diets and incorporating more whole foods as the GAPS diet does is something that almost everyone can get behind.

How the GAPS does this, however, is more complex than it needs to be and can be potentially harmful, especially if those trying the GAPS diet forgo evidence-based treatments.

The bottom line

The GAPS diet was created by neurologist Cambell-McBride who claims to have successfully treated thousands of patients with various chronic inflammatory diseases that affect the brain, digestive system, and hormones.

It involves a two-step diet protocol in combination with nutritional supplementation and various detoxing strategies.

Components of the diet may improve gut health — especially if you follow a Western-style diet — and it may be useful for identifying foods or ingredients to which you may intolerant or allergic.

However, there is no evidence that the GAPS diet can cure the diseases it claims to treat. It can also be difficult to follow due to its rigid diet rules and time-consuming qualities.

It’s essential to consider both the pros and cons in determining whether the GAPS diet is right for you.


Gavin Van De Walle, MS, RD, LN
Gavin Van De Walle, MS, RD, LN

Gavin Van De Walle holds a master's degree in human nutrition and bioenergetics. He is a registered dietitian who aims to arm the public with evidence-based nutrition recommendations so they can make their own educated and informed health decisions.