by The GAPS diet is a type of elimination diet aimed at healing the gut and promoting overall gut health. The premise behind the diet is that some health conditions, particularly digestive disorders and various neurological conditions – such as autism and attention deficit hyperactivity disorder (ADHD) – can be caused by something called intestinal hyperpermeability scientifically, commonly known as leaky gut. The GAPS diet claims that leaky gut healing may improve or cure these conditions.
However, there is a lack of research and scientific evidence to support the GAPS diet. Let’s take an in-depth look at what the GAPS diet requires to treat, how to follow it, what you can and cannot eat, and the benefits and risks associated with the GAPS diet guidelines.
What is the GAPS diet?
GAPS stands for Gut and Psychology Syndrome, a term coined by Natasha Campbell-McBride, who has degrees in medicine, neuroscience and nutrition, to describe connections between the digestive system and the brain. Campbell-McBride created the GAPS diet in 2004 after researching the relationship between food, nutrition, gut and brain health while looking for answers for her own child who was diagnosed with a learning disability. She has since added Gut and Physiological Syndrome (still GAPS) to Gut and Psychological Syndrome, which concerns the possible role of the gut in a number of chronic physical conditions.
According to the GAPS diet website, GAPS theorizes that many health conditions are rooted in an unhealthy gut, and if one’s gut is healed, various digestive, neurological and autoimmune conditions may also be resolved. These claims are made in relation to conditions including 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 GAPS diet claims.
It is 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 UK-based clinic.
What Can You Eat on the GAPS Diet?
Introduction Diet
There are three phases of the GAPS diet: introduction, the full GAPS diet and reintroduction. There is also a dairy introduction phase, which is explained in detail in the books. For those who want to follow the diet, Campbell-McBride recommends you buy the books, Gut Syndrome and Psychology and Gut and Physiological Syndrome, so you can follow each step as suggested.
The Introductory Diet has six steps, with the goal of healing leaky gut before moving on to the full GAPS diet. The intestinal lining is made up of cells designed to absorb water and nutrients and get them into the bloodstream. Think of this intestinal lining as a protective barrier. If this barrier gets holes or cracks, undigested food and toxic bacteria can leak into the body, causing inflammation and digestive problems. This is called intestinal hyperpermeability or leaky gut.
The basic foods in the introduction phase include meat stocks and broths, soups and fermented foods. The length of time you stay in each stage varies anywhere from three to five days or four to six weeks or more. Once diarrhea or other serious digestive symptoms have resolved, you can move on to the next step. Campbell-McBride says it’s important to introduce small amounts of foods slowly as you move through the stages to see what you can tolerate. The following are the foods allowed in the six stages of the Introduction Diet:
Step 1: Homemade meat or fish stock; homemade soups with meat or fish stock; dairy or vegetable based probiotic foods; ginger tea.
Step 2: Continue with foods in Step 1. Add raw organic egg yolks; stews or casseroles made with meat and vegetables; homemade yogurt or kefir; juice from sauerkraut or vegetables; fermented fish; domestic ghee.
Step 3: Add ripe avocado; GAPS pancakes (recipe in book); eggs scrambled with ghee, goose fat or duck fat; sauerkraut; fermented vegetables.
Step 4: Gradually add roasted and grilled meat; cold-pressed olive oil; freshly squeezed juices; bread baked with peanuts or seeds.
Step 5: Add cooked apple puree and raw vegetables, starting with lettuce and peeled cucumber. Avoid citrus.
Step 6: Add peeled raw apple; add other raw fruit and honey as added.
complete GAPS diet
The complete GAPS diet introduces more foods aimed at healing and restoring the gut, according to Campbell-McBride. She recommends people follow the full GAPS diet for 18 months to two years. On the diet, about 85% of the foods you eat daily should be from:
- Meat
- Fish
- Broth
- Eggs
- Fermented foods
- Vegetables
Fruit is also fine, as are baked goods made with nut flour or seeds. See below for a more extensive list of foods you can and cannot eat.
Restoration Phase
After six months of normal digestion and bowel movements, you can begin the recovery phase. During this time, you can start to put foods back into your diet, slowly and a little at a time, to see how you tolerate them. If you have no symptoms, you can increase portions.
There is no exact order of foods to reintroduce; however, Campbell-McBride recommends starting with potatoes and fermented gluten-free grains. She also recommends that people following 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
- Fish
- Shellfish
- Fresh vegetables
- Results
- Nuts
- Seeds
- garlic
- Olive oil
Foods You Can’t Eat on the GAPS Diet
- Grain
- Sugar
- Potatoes
- Parsnips
- Soy
- Commercial yogurt
- Homemade cheese
- Rice
- Oats
- Coffee
- Cup
- Artificial sweeteners
- All processed food in packages or tins
- Milk from any animal; soymilk, rice milk or canned coconut milk
Other GAPS diet recommendations
- Eat fresh and frozen meat from high quality sources only – no tinned, smoked or processed meat
- Eat only wild fish, fresh or frozen
- Consume only cold-pressed, organic, raw plant oils
- Cook with animal fat, coconut oil or ghee only
- Do not microwave food
It is important to reiterate that there is little, if any, scientific support for the restriction and specificity of this diet. Additionally, meat and seafood can come from quality sources even if they are canned, even though the diet excludes canned foods (still confused?).
Are There Benefits to the GAPS Diet?
The GAPS diet emphasizes vegetables and fermented foods, both of which are linked to a healthy gut. Studies, like the 2022 review i Microorganismssuggest that eating a variety of fruit and vegetables, olive oil and fatty fish can help maintain a healthy balance of bacteria in the gut, but a diet high in saturated fat and refined carbohydrates and low in fiber – or a traditional diet the West – to cause an imbalance of gut bacteria.
Review 2022 i Nutrients suggests that fermented foods like kefir and sauerkraut, as well as probiotic-rich foods like yogurt, can help improve gut microbiota. And limiting highly processed foods with 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, like the 2021 review in Limits in Nutritionconsumption of artificial sweeteners has been shown to alter gut bacteria.
Disadvantages of the GAPS diet
There are no peer-reviewed clinical studies evaluating the GAPS diet or proving it to be effective in healing the gut and treating the conditions it claims to heal. In addition, it is not clear if leaky gut is the result of a certain condition and not the cause.
Although scientists agree that leaky gut can occur, research has not shown that improving the intestinal barrier cures or improves any specific conditions, according to a 2019 review published in the journal. Gut.
The GAPS diet is extremely restrictive, which has several consequences. At first, this makes planning and cooking meals time-consuming. More concerning, however, is that the diet was originally developed to help children suffering from behavioral and digestive problems. Putting children – or adults for that matter – on an extremely restrictive diet can lead to malnutrition and/or disordered eating patterns. Not to mention, very restrictive plans aren’t usually enjoyable or sustainable over a long period of time, negating any results they might promise. In addition, it appears to be gluten free as it does not allow any grain.
It is extremely important to weigh the risks and benefits of the GAPS diet, especially since there is no substantial evidence that it provides any health benefits and that it may cause harm.
Sample GAPS diet meal plan
Breakfast
Scramble eggs 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
Dinner
Lemon-garlic salmon with homemade tzatziki (Greek yogurt, lemon juice, cucumber, dill)
Roasted Brussels sprouts and butternut squash
The Bottom Line
So, should you try the GAPS diet? In my opinion, no. This dietitian does not recommend the GAPS diet, since there is no research to support its claims or effectiveness. In addition, it is extremely restrictive, time-consuming and relatively expensive. There are more effective, science-backed ways to improve digestive and neurological disorders that involve small, sustainable changes. We highly recommend working with a gastroenterologist who can diagnose your condition and a registered dietitian nutritionist (RDN) who specializes in that condition and can provide specific solutions tailored to your food choices and lifestyle.
