The GAPS diet is a type of elimination diet that aims to heal the gut and support overall gut health. The basic premise behind the diet is that a number of health conditions, particularly digestive disorders and neurodivergent conditions (autism and attention deficit hyperactivity disorder (ADHD)), can be caused by what is scientifically known as intestinal hyperpermeability, commonly referred to as leaky gut. The GAPS diet claims that healing a leaky gut can improve or cure these conditions.
However, there is a lack of research and scientific evidence to support the GAPS diet. Let’s take a deep dive into what the GAPS diet treats, how to follow it, what you can and can’t eat, and the benefits and risks of the GAPS diet guidelines.
What is the GAPS Diet?
GAPS stands for Gut and Psychology Syndrome, a term developed by Natasha Campbell-McBride, who holds degrees in medicine, neurology and nutrition, to describe the connections between the digestive system and the brain. Campbell-McBride created the GAPS diet in 2004 after researching the relationship between food, nutrition, the gut and brain health while seeking answers for her own child, who had been diagnosed with a learning disability. She has since added Gut and Psychology Syndrome to Gut and Physiology Syndrome (still GAPS), which deals with the potential role of the gut in some chronic physical conditions.
According to the GAPS diet website, GAPS assumes that many health conditions are caused by an unhealthy gut and that if a person’s gut is healed, various digestive, neurological and autoimmune conditions can also be resolved. These claims relate to conditions such as autoimmune diseases such as celiac disease, Crohn’s disease and rheumatoid arthritis; food allergies and intolerances; thyroid disorders; and other digestive disorders such as irritable bowel syndrome (IBS). Neurological and psychiatric conditions such as autism, ADHD, schizophrenia and bipolar disorder are also included in the GAPS diet claims.
It’s important to note that there are no peer-reviewed scientific studies examining the effectiveness of the GAPS diet. Most of the success stories are anecdotal and come from Campbell-McBride’s books and her clinic in the UK.
What Can You Eat On The GAPS Diet?
Introduction Diet
There are three phases to the GAPS diet: introduction, full GAPS diet, and reintroduction. There is also a dairy introduction phase, which is explained in more detail in the books. For those who want to follow the diet, Campbell-McBride recommends purchasing the books, Gut and Psychology Syndrome And Intestinal and Physiology Syndrome, so you can follow each step as suggested.
The Introduction Diet consists of six stages, and the goal is to heal leaky gut before moving on to the full GAPS diet. The intestinal lining is made up of cells that need to absorb water and nutrients and move them into the bloodstream. Think of this intestinal lining as a protective barrier. If holes or cracks form in this barrier, undigested food and toxic bacteria can leak into the body, causing inflammation and digestive problems. This is called intestinal hyperpermeability, or leaky gut.
Staple foods in the Introduction phase include broths and stocks, soups, and fermented foods. How long you stay in each phase varies from three to five days or four to six weeks or more. Once diarrhea or other severe digestive symptoms have resolved, you can move on to the next phase. Campbell-McBride says it’s important to introduce small amounts of foods slowly to see what you can tolerate as you progress through the phases. Foods allowed in the six phases of the Introduction Diet include:
1 stage: Homemade meat or fish stock; homemade soups made with meat or fish stock; dairy or vegetable-based probiotic foods; ginger tea.
Stage 2: Continue with foods from Phase 1. Add raw organic egg yolks; stews or casseroles made with meat and vegetables; homemade yogurt or kefir; sauerkraut or vegetable juice; fermented fish; homemade ghee.
Scene 3: Add ripe avocado; GAPS pancakes (recipe in book); eggs beaten with ghee, goose fat or duck fat; sauerkraut; fermented vegetables.
Stage 4: Gradually add roasted and grilled meats, cold-pressed olive oil, freshly squeezed fruit juices, and baked bread with ground nuts or seeds.
Stage 5: Add cooked applesauce and raw vegetables, starting with lettuce and peeled cucumber. Avoid citrus fruits.
Stage 6: Add peeled raw apple; add other raw fruits and honey as tolerated.
Full GAPS Diet
According to Campbell-McBride, the full GAPS diet offers more foods that aim to heal and repair the gut. She recommends people follow the full GAPS diet for 18 months to two years. On the diet, about 85% of the foods you consume daily should be:
- Meat
- Fish
- Meat Water
- Eggs
- Fermented foods
- vegetables
Baked goods made with fruit and nut or seed flours are also OK. See below for a more comprehensive list of foods you can and cannot eat.
Reintroduction Phase
After six months of normal digestion and bowel movements, you can begin the reintroduction phase. During this time, you can slowly and gradually add foods back into your diet to see how you tolerate them. If you have no symptoms, you can increase the portions.
There is no specific order of foods to reintroduce, but Campbell-McBride suggests starting with potatoes and fermented gluten-free grains. She also recommends that people on the GAPS diet continue to avoid highly processed foods and foods high in added sugar.
GAPS Diet Food List
For a comprehensive list of foods you can and cannot eat, see the GAPS website and books.
Foods You Can Eat on the GAPS Diet
- Eggs
- Meat
- Stock up
- Fish
- Shellfish
- Fresh vegetables
- Fruit
- Hazelnut
- Seeds
- Garlic
- Olive oil
Foods You Cannot Eat on the GAPS Diet
- Grains
- Sugar
- Potatoes
- Wild Carrots
- Soy
- Commercial yogurt
- Cottage cheese
- Rice
- Oat
- Coffee
- Sweetcorn
- Artificial sweeteners
- All processed foods that are packaged or boxed
- Milk from any animal; soy milk, rice milk, or canned coconut milk
Other GAPS Diet Suggestions
- Eat only fresh and frozen meat from high-quality sources; avoid canned, smoked or processed meats
- Consume only wild-caught, fresh or frozen fish
- Consume only cold-pressed, organic, raw vegetable oils
- Cook only with animal fat, coconut oil or ghee
- Do not heat food in the microwave
It’s important to reiterate that there is little, if any, scientific support for the restrictiveness and specificity of this diet. Additionally, meats and seafood, even if canned, can come from high-quality sources, but the diet excludes canned foods (confused?).
Are There Any Benefits to the GAPS Diet?
The GAPS diet emphasizes vegetables and fermented foods, both of which have been linked to a healthy gut. Studies like one 2022 review MicroorganismsThey suggest that consuming a variety of fruits and vegetables, olive oil and oily fish may help maintain a healthy balance of bacteria in the gut, while a diet high in saturated fat and refined carbohydrates and low in fibre (i.e. the traditional Western diet) may lead to an imbalance in gut bacteria.
A review in 2022 Nutrients suggests that fermented foods like kefir and sauerkraut, along with probiotic-rich foods like yogurt, may help improve gut microbiota. And limiting highly processed foods that contain added sugar, refined grains, and artificial sweeteners is also beneficial for overall health. Refined carbohydrates and sugar can increase inflammation in the body, and some studies, such as a 2021 review Limits in NutritionIt showed that consumption of artificial sweeteners can alter gut bacteria.
Disadvantages of the GAPS Diet
There are no peer-reviewed clinical studies evaluating the GAPS diet or proving that it is effective in healing the gut and treating the conditions it claims to. Additionally, it is unclear whether leaky gut is the result of having a specific condition or whether it is the cause.
While scientists agree that intestinal permeability can occur, no research has shown that improving the intestinal barrier treats or cures any specific condition, according to a review published in the Journal of Medicine in 2019. Bowel.
The GAPS diet is extremely restrictive, and this has several consequences. For starters, it makes meal planning and cooking time-consuming. More concerning, however, is that the diet was originally developed to help children with behavioral and digestive issues. Putting children or adults on an overly restrictive diet can lead to malnutrition and/or disordered eating habits. Additionally, overly restrictive plans are often not enjoyable or sustainable over the long term, which can lead to the results they may promise. It also appears to be gluten-free, as it does not allow any grains.
It is extremely important to weigh up the risks and benefits of the GAPS diet, especially given the lack of significant evidence of any health benefits and the potential for harm.
Sample GAPS Diet Meal Plan
Breakfast
Egg Scramble with Zucchini, Spinach, Tomatoes and Gorgonzola Cheese
Lunch
Spinach salad with broccoli, carrots, tomatoes, chicken, avocado, walnuts and blue cheese
Homemade dressing with olive oil and apple cider vinegar
Evening meal
Lemon-garlic salmon with homemade tzatziki (Greek yogurt, lemon juice, cucumber, dill)
Roasted Brussels sprouts and zucchini
Underline
So, should you try the GAPS diet? I think not. This dietitian does not recommend the GAPS diet because there is no research to support its claims or effectiveness. It is also extremely restrictive, time-consuming, and relatively expensive. There are more effective, scientifically supported ways to improve digestive and neurological disorders that involve small, sustainable changes. We strongly recommend working with a gastroenterologist who can diagnose your condition and a registered dietitian nutritionist (RDN) who specializes in this condition and can offer customized solutions tailored to your food preferences and lifestyle.