What Is the GAPS Diet?

chicken broth with vegetables in bowl

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In This Article

The GAPS diet is not a weight-loss diet—instead, it's intended as a natural treatment for autism, attention deficit hyperactivity disorder, dyslexia, and other mental illnesses. In fact, "GAPS" stands for "gut and psychology syndrome." Parents who are seeking alternative therapies for children who have been diagnosed with these conditions may turn to this diet.

The diet itself claims to "heal the gut" by eliminating many foods considered problematic, including grains and dairy, and by adding foods with natural probiotics. Although many people attest that the diet has worked for them or for their child, there aren't any strong medical studies or other research showing effectiveness.

What Experts Say

"According to the GAPS diet, eliminating many foods allows the gut to “heal and seal.” There is little evidence to support these claims. Experts worry the numerous restrictions—including grains, most dairy, and starchy vegetables—increases the risk of nutrient deficiencies."

Chrissy Carroll, RD, MPH


The GAPS diet was developed by Natasha Campbell-McBride, M.D., who received her medical degree in Russia and who later received two post-graduate degrees, one in neurology and the other in nutrition. After she moved to the United Kingdom, her son was diagnosed with autism, which led her on a search for an effective autism treatment.

Dr. Campbell-McBride published her first book, Gut And Psychology Syndrome. Natural Treatment Of Autism, ADHD, Dyslexia, Dyspraxia, Depression And Schizophrenia, in 2004. In it, she explored what she sees as the connections between brain health and gut health, and described a diet, the "GAPS Nutritional Protocol," that she said has been highly successful in treating patients with learning disabilities and other mental problems.

The GAPS diet, which originally was based on another diet used to treat celiac disease and inflammatory bowel disease, relies heavily on homemade broths and fermented vegetables.

It's designed to heal what Dr. Campbell-McBride believes is damage to the gut wall, or "leaky gut syndrome." Healing the gut, she says, also can help ease symptoms of mental conditions. Many children with autism also suffer from significant digestive problems, including diarrhea, constipation, and bloating.

How It Works

The GAPS diet features an introductory phase (with very limited food selection) and a "full" diet phase, which allows a wider variety of foods. Dr. Campbell-McBride urges everyone to try the introductory phase before moving on to the entire diet. However, only those whose conditions are particularly severe need to stay in the introductory phase for very long.

The introductory phase allows only: homemade meat, chicken, or fish stock; homemade soup made with stock plus non-starchy vegetables; homemade fermented foods such as sauerkraut or vegetables; homemade fermented dairy products; organic egg yolks; and avocado.

Gradually, as digestive symptoms subside, you can add: pancakes made from nut butter and vegetables; homemade ghee; fried eggs; roasted and grilled meats; olive oil; bread made with almond flour; cooked apple; raw vegetables; homemade juice; and raw apples.

Once the patient can eat all of those items without digestive symptoms, then they're ready for the full GAPS protocol.

Compliant Foods
  • Meat, poultry, fish, and eggs

  • Non-starchy vegetables

  • Most fruit

  • Fermented dairy (yogurt, kefir, and ghee)

  • Fermented fish (using GAPS recipe)

  • Fermented vegetables

  • Homemade vegetable and fruit juice

  • Nuts, nut butters, and nut flour

  • Butter

  • Olive oil

  • Coconut oil

  • Honey

Non-Compliant Foods
  • All grains (wheat, rice, barley, oats, and corn) and everything made with them (bread, breakfast cereal, and pasta)

  • Starchy vegetables (potatoes, parsnips, yams, and sweet potatoes)

  • Quinoa, buckwheat, sorghum, millet (and other "gluten-free" grains

  • Sugar and anything that contains it

  • Maple syrup, molasses, corn syrup, and any other syrup

  • Aspartame in any form, and any food that contains it

  • Candy, cookies, cakes, and ice cream

  • Milk (unless it's fermented)

  • All processed foods

  • All alcoholic beverages

Here's a rundown of the foods that are allowed (and aren't allowed) on the GAPS diet protocol:


Meats, Poultry, and Fish

The GAPS diet protocol allows all types of animal protein. However, you'll need to cook them and serve them only with allowed sauces and spices, which means you'll be making them at home for the most part.

Vegetables (Some)

Some allowed, some not allowed. Non-starchy vegetables are encouraged on the GAPS diet, and in fact you're urged to ferment them using recipes and cultures that are "GAPS-approved." Non-starchy vegetables include carrots, onions, asparagus, broccoli, cabbage, Brussels sprouts, cauliflower, kale, Swiss chard, lettuce, and beets.


Virtually all allowed. Bananas are the only type of fruit that comes with a modification on the diet: try to eat only very ripe bananas. If they have brown spots on them, they're ready.


Grain Based Foods

These include multiple foods that are staples in most people's diets, including bread, cereal, crackers, pasta, cakes, cookies, and all other conventional baked goods. Dr. Campbell-McBride believes that these foods irritate the gut lining and ultimately damage it, which affects how nutrients are absorbed.

Dairy-based foods.

Only fermented versions allowed in most cases. Milk—particularly cow's milk—can irritate and damage the intestinal lining in much the same way as grains do, according to Dr. Campbell-McBride's theory. Fermented versions of dairy-based foods do not have this effect. Therefore, nearly the only dairy-based foods allowed on the GAPS diet are homemade fermented foods: yogurt, kefir, ghee, and whey. The exception is butter, which is allowed.

Dr. Campbell-McBride encourages fermented dairy and says you can add it beginning in the introductory phase of the diet.

Certain Vegetables

Vegetables that are not allowed on the diet include potatoes, sweet potatoes, parsnips, and yams. Beans and legumes also are banned on the GAPS diet.

Sugar and anything with sugar in it

Under the diet, sugar is considered toxic for your gut lining. The complete ban on sugar (and on ingredients such as maple syrup, molasses, and aspartame) means you'll need to steer clear of virtually all processed foods.

Processed foods and alcoholic beverages

All processed foods (with the exception of the very few that are specifically labeled "GAPS-compliant") contain ingredients that are off-limits under the diet. In addition, alcoholic beverages are not allowed.

Recommended Timing

Dr. Campbell-McBride recommends that people hoping to get good results from the GAPS diet start with the introductory phase and stay on it (working through its six stages) for as long as it takes for their digestive symptoms to subside. Once digestive symptoms have abated, she says, they can move on to the full GAPS diet and add more foods.

It takes at least one-and-a-half to two years on the GAPS diet protocol before those following the plan can begin to eat non-compliant foods again.

"Your patient needs to have at least six months of normal digestion before you start introducing foods not allowed on the GAPS diet. Do not rush with this step," she says. Some people take longer than two years to be ready for non-GAPS foods.

The first foods to introduce once you're ready to come off the diet include new potatoes and fermented gluten-free grains.

Resources and Tips

Following the GAPS diet means you'll cook virtually all your own food from scratch. In many cases, you'll use homemade meat or fish stock for soups, broths, and other recipes. Dr. Campbell-McBride believes that homemade stock has a "soothing effect" on areas of inflammation within the intestinal tract. Commercial stock products don't have this same effect, she says.

To make homemade meat or poultry stock, you'll need to start with bones and joints with a bit of meat on them. Place them in a large pan and fill the pan up with water. Add a bit of sea salt and a few herbs to taste, bring it to a boil, and then cover and simmer it on low heat for 2 1/2 to 3 1/2 hours. If you prefer, use a slow cooker and simmer the mixture on low overnight. To make homemade fish stock, use the entire fish or fish fins, and cook it for up to 1 1/2 hours.

Fermented foods also are recommended as a source of beneficial bacteria. Dr. Campbell-McBride's book includes recipes for sauerkraut, fermented vegetables, and fermented probiotic beverages.


Dr. Campbell-McBride urges those considering the GAPS diet to follow it strictly according to the blueprint in her book. That makes it difficult to modify. Vegetarians may find the diet is tricky to follow, since the GAPS diet depends on animal-based protein.

However, the diet already is gluten-free, corn-free, and peanut-free, and easily can be made dairy-free if you have an allergy or an intolerance to dairy foods. Those with a tree nut allergy will need to avoid certain recipes, but shouldn't have much trouble finding foods they can eat on the GAPS diet.

Pros and Cons

  • Encourages healthy home-cooked meals

  • May help some people

  • Strong online community

  • Little research showing it's effective

  • Very difficult to maintain

  • Eliminates multiple foods


There's no question that the GAPS diet encourages home-cooked meals made from fresh vegetables, fruits, meats, poultry, and fish. No junk food, fast food, or even restaurant-made food is allowed on the diet. Given that, the GAPS diet will be a healthier diet than the typical American diet.

There's also some anecdotal evidence direct from parents and others that the diet does help improve symptoms of autism, ADHD, and other mental conditions in children and adults who follow it. Dr. Campbell-McBride maintains a list of physicians whom she has trained on the diet.

Finally, there's a strong online community that can help you start and continue the diet. Parents and others who have implemented the GAPS diet will answer questions, provide support, and often act as cheerleaders for those just beginning the diet.


Like most diet treatments for autism, the GAPS diet has no rigorous medical studies to back it up. Unfortunately, there's little medical evidence to indicate that any of Dr. Campbell-McBride's recommendations—ranging from homemade broth to fermented foods—can help improve symptoms of autism or related disorders.

In fact, some medical professionals warn that cutting out so many healthy foods—such as whole grains and legumes—can lead to nutritional deficiencies in children and adults who follow the diet. The GAPS diet is extremely restrictive, and also could lead to unintended weight loss.

Finally, the GAPS diet is extremely difficult to follow. You'll need to cook all your own food from scratch—no store-bought convenience foods, such as broth or most sauces, are allowed. Many parents following the GAPS diet find that they're spending many more hours in the kitchen than they ever had before.

How It Compares

The GAPS diet is intended to treat mental health conditions and learning disabilities. It's not intended to be a weight loss diet. It's a grain-free diet that eliminates all sugars and simple starches.

USDA Recommendations

The U.S. Department of Agriculture (USDA) recommends that people get a significant portion of their daily calories—more than one-quarter—from grain-based products, preferably whole grains. These include bread, cereal, pasta, rice, tortillas, and grits. Since the GAPS diet does not include any grains, it's far from ideal, according to USDA recommendations.

The USDA's ChooseMyPlate tool also recommends that people get around one-half of their daily food allotment from fruits and vegetables. Here, the GAPS diet comes much closer to the USDA's nutritional advice; in fact, it's likely that people following the GAPS diet will eat more vegetables and fruits than the diet tool wants to see.

When it comes to protein-based foods, such as meat, poultry, fish, legumes, and nuts, the GAPS diet also somewhat closely tracks the overall USDA recommendations, which call for around one-quarter of your daily calories to come from protein foods. However, the GAPS diet does not allow legumes, which are a great source of protein and fiber.

Finally, dairy products are allowed for most people on the GAPS diet, and fermented dairy (yogurt and kefir) is preferred. The USDA calls for daily calcium-containing dairy products.

Similar Diets

Specific Carbohydrate Diet

The GAPS diet was developed from the Specific Carbohydrate Diet (SCD), and the two are quite similar: they both eliminate all grains and simple starches, and they both rely on fermented dairy products to restore balance in the intestinal lining.

Still, the GAPS diet is intended for children and adults with autism and other mental disorders, while the SCD targets people with inflammatory bowel disease (although some parents have used SCD to treat autism spectrum disorders).

Gluten-Free, Casein-Free Diet

The gluten-free, casein-free (GFCF) diet is the most common diet used by families for children with autism and related conditions. It eliminates all gluten (found in wheat, barley, and rye) and all casein (found in milk and milk-containing products). The theory behind the diet is that people with autism spectrum disorders have trouble digesting the gluten and casein proteins, which are similar in structure to each other.

Like the GFCF diet, the GAPS diet eliminates gluten-containing foods (although it does allow dairy). But the GAPS diet also eliminates gluten-free grains such as rice and corn, while the gluten-free diet allows them.

A Word from Verywell

Autism, ADHD, and related disorders can be devastating, and it's understandable that parents would want to do whatever they can to help their children. However, the GAPS diet requires a tremendous, ongoing commitment—it's not for the faint of heart, nor is it the best diet for a family that's accustomed to grabbing food on the run.

If you're considering the GAPS diet, make sure to speak with your doctor or your child's pediatrician to make certain it's the best choice for you and your family.

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Article Sources
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  • Campbell-McBride, Natasha. Gut and Psychology Syndrome: Natural Treatment for Autism, Dyspraxia, A.D.D., Dyslexia, A.D.H.D., Depression, Schizophrenia. Medinform Pub., 2010.