The Gut and Psychology Syndrome (GAPS) diet is an elimination diet developed by Dr. Natasha Campbell-McBride in 2004. It's designed to address conditions affecting the brain, such as autism spectrum disorder (ASD), by focusing on gut health. The diet's core principle is that a "leaky gut" allows harmful substances to enter the bloodstream, affecting brain function and development. While the GAPS diet has gained popularity as a natural treatment for various conditions, it remains a controversial approach with limited scientific evidence.
Understanding the GAPS Diet
The GAPS diet is based on the theory that a compromised gut lining, often referred to as "leaky gut," increases intestinal permeability. This condition allows chemicals, toxins, and bacteria to enter the bloodstream, potentially affecting brain function and development. Dr. Campbell-McBride, inspired by the Specific Carbohydrate Diet (SCD), developed the GAPS diet to heal the gut and prevent these harmful substances from reaching the brain. The diet aims to reduce inflammation and toxin exposure, leading to improvements in behavioral and psychological symptoms.
What is "Leaky Gut"?
The term "leaky gut" describes an increase in the permeability of the gut wall. While it's not recognized as an official medical diagnosis, it suggests that the gut lining is more porous than it should be. The GAPS theory claims that this increased permeability allows substances that wouldn't normally pass through the gut wall to enter the bloodstream.
Conditions the GAPS Diet Claims to Address
The GAPS diet is promoted as a natural treatment for a range of psychiatric and neurological conditions, primarily affecting children. These include:
- Autism spectrum disorder (ASD)
- Attention deficit disorder (ADD)
- Attention deficit hyperactivity disorder (ADHD)
- Dyspraxia
- Dyslexia
- Depression
- Schizophrenia
- Tourette syndrome
- Bipolar disorder
- Obsessive-compulsive disorder (OCD)
- Eating disorders
- Gout
- Childhood bedwetting
- Food intolerance or allergy
The GAPS Diet Protocol: Stages and Guidelines
The GAPS diet involves a structured approach with three main phases: Introduction, Full GAPS Diet (Maintenance), and Reintroduction. Each phase has specific guidelines and food restrictions designed to heal the gut and gradually reintroduce foods.
Read also: Starting the GAPS Diet
1. The Introduction Diet
The Introduction Diet is the most restrictive phase, often called the "gut healing phase." It can last from three weeks to one year, depending on individual symptoms and tolerance. This phase is divided into six stages, each introducing new foods while eliminating others.
- Stage 1: Focuses on homemade bone broth, juices from probiotic foods (like fermented vegetable juice), and ginger, mint, or chamomile tea with honey. Unpasteurized, homemade yogurt or kefir is allowed for those who are not dairy intolerant.
- Stage 2: Adds raw organic egg yolks, ghee, and stews made with vegetables, meat, or fish.
- Stage 3: Includes all previous foods plus avocado, fermented vegetables, GAPS-recipe pancakes (made with nut flours), and scrambled eggs cooked in ghee, duck fat, or goose fat.
- Stage 4: Introduces grilled and roasted meats, cold-pressed olive oil, vegetable juice, and GAPS-recipe bread.
- Stage 5: Adds cooked apple purée, raw vegetables (starting with lettuce and peeled cucumber), fruit juice, and small amounts of raw fruit (excluding citrus).
- Stage 6: Incorporates more raw fruit, including citrus.
During the Introduction Diet, it's crucial to introduce foods slowly and monitor for any adverse reactions. Individuals can move to the next stage once they can tolerate the newly introduced foods, indicated by normal bowel movements.
2. The Full GAPS Diet (Maintenance)
The Full GAPS Diet, or maintenance phase, typically lasts 1.5 to 2 years. This phase emphasizes nutrient-dense foods that support gut health while continuing to avoid those that are difficult to digest.
Recommended foods include:
- Fresh meat, preferably hormone-free and grass-fed
- Animal fats, such as lard, tallow, lamb fat, duck fat, raw butter, and ghee
- Fish and shellfish
- Organic eggs
- Fermented foods, such as kefir, homemade yogurt, and sauerkraut
- Vegetables
- Moderate amounts of nuts and GAPS-recipe baked goods made with nut flours
Additional recommendations for the Full GAPS Diet:
Read also: Understanding the GAPS Diet
- Avoid eating meat and fruit together.
- Use organic foods whenever possible.
- Consume animal fats, coconut oil, or cold-pressed olive oil at every meal.
- Consume bone broth with every meal.
- Consume large amounts of fermented foods, if tolerated.
- Avoid packaged and canned foods.
- Avoid all other foods, particularly refined carbs, preservatives, and artificial colorings.
3. The Reintroduction Phase
The Reintroduction Phase is initiated after experiencing normal digestion and bowel movements for at least six months on the Full GAPS Diet. This phase involves gradually reintroducing foods that were previously eliminated.
The diet suggests introducing each food individually in small amounts. If no digestive issues arise over 2 to 3 days, the portion size can be gradually increased. The diet doesn't specify the order or exact foods to reintroduce but recommends starting with new potatoes and fermented, gluten-free grains.
Even after completing the GAPS diet, it's advised to continue limiting ultra-processed and refined high-sugar foods, adhering to the whole-foods principles of the protocol.
Foods to Eat and Avoid on the GAPS Diet
Foods to Eat
- Meat stock (cooked shorter than broth and contains less glutamates)
- Meats, preferably hormone-free or grass-fed
- Fish
- Shellfish
- Animal fats
- Eggs
- Fresh fruits and non-starchy vegetables
- Fermented foods and beverages
- Hard, natural cheeses
- Kefir
- Coconuts, coconut milk, and coconut oil
- Nuts
- Dry wine
- White navy beans
Foods to Avoid
- Sugar and artificial sweeteners
- Syrups
- Alcohol (small amounts of dry wine occasionally allowed for adults)
- Processed and packaged foods
- Grains such as rice, corn, wheat, and oats
- Starchy vegetables, such as potatoes and yams
- Milk
- Beans (except white and green beans)
- Coffee
- Strong teas
- Soy
Potential Benefits of the GAPS Diet
While anecdotal reports suggest various benefits, scientific evidence supporting the GAPS diet's effectiveness is limited. Some potential benefits include:
- Reduced inflammation: Proponents claim that removing potential inflammatory triggers like grains and refined carbohydrates can reduce inflammation in the body.
- Support for digestive issues: The GAPS diet is technically a low-FODMAP diet, which may help people with irritable bowel syndrome or other inflammatory bowel conditions.
- Improving behavioral and psychological conditions: There is some research suggesting that a healthy gut microbiome could ease depressive and anxiety symptoms. Some case studies written with the diet’s creator have claimed that the GAPS diet might impact these and other health issues.
Potential Risks and Criticisms of the GAPS Diet
The GAPS diet is a highly restrictive protocol with potential risks:
Read also: Comprehensive review of the GAPS Diet
- Risk of malnutrition: The diet eliminates many nutrient-rich foods, increasing the risk of nutrient deficiencies, especially in children.
- Restrictive for children with ASD: Those with ASD may already have restrictive diets and may not readily accept new foods or changes to their diets, potentially leading to extreme restriction.
- Elevated cholesterol: The diet relies heavily on meats and animal fats, which can be high in saturated fat and could increase cholesterol.
- Lack of scientific evidence: There is little published, peer-reviewed research on the GAPS diet’s ability to improve the brain-gut connection and ultimately treat the variety of conditions it claims to.
- Potential for disordered eating: This diet encourages restriction of many foods and can lead to increased preoccupation about - and avoidance of - certain foods, which are two characteristics of disordered eating.
Scientific Evidence and Research
Limited research has examined the effects of the GAPS diet on the symptoms and behaviors associated with ASD. Some studies suggest that it may help manage gastrointestinal symptoms, which can, in turn, prevent or reduce the severity of certain behaviors. Other studies performed by the International Society for Orthomolecular Medicine found that the GAPS diet had a positive effect on conditions like PANDAS, tic-related disorders, and various chronic diseases. However, these studies have been small, and dropout rates are high, so it’s still unclear whether these diets may work and which people they may help. More research is needed to understand the role of the GAPS diet in managing neurodivergent conditions.
Research on dietary supplements, such as probiotics and omega-3 fatty acids, may offer a more promising line of inquiry. For instance, a 2019 study found that children with ASD had different gut microbiota compared to neurotypical children, and probiotic supplementation was beneficial. A small 2021 study found that taking omega-3 fatty acid supplements had some positive effect on ASD behaviors.
Consulting Healthcare Professionals
Given the restrictive nature of the GAPS diet and the potential risks, it's crucial to consult with healthcare professionals before starting the diet. A healthcare provider can assess individual needs and determine if the GAPS diet is appropriate. Working with a registered dietitian can help ensure adequate nutrient intake and prevent deficiencies.
The Gut-Brain Connection
The GAPS diet is inspired by research exploring the connection between the gastrointestinal tract and the brain. The GAPS diet claims are built on research that explores a two-way communication pathway between our gut and our brain. Proponents of GAPS believe that certain neurological and psychological conditions can be treated by adhering to a specific diet.
Current research around diet and the brain is limited to studies on anxiety and depression.