The GAPS diet - Gut and Psychology Syndrome - was developed by Dr Natasha Campbell-McBride, a Russian neurologist who believed she cured her son's autism through dietary intervention. The protocol claims to heal "leaky gut" and, by extension, treat conditions ranging from autism and ADHD to depression and schizophrenia.
It's a bold set of claims. And while the diet includes some genuinely useful elements, the scientific evidence for its central premises remains extremely thin.
Important Note
The GAPS diet makes claims about treating serious medical conditions including autism, ADHD, depression, and autoimmune disorders. These claims are not supported by peer-reviewed research. If you're managing any of these conditions, work with qualified healthcare professionals.
What Is the GAPS Diet?
GAPS is an elimination diet that removes grains, starchy vegetables, refined carbohydrates, and most processed foods. It emphasises bone broth, fermented foods, and eventually reintroduces a limited range of whole foods.
The theory: a damaged gut lining allows toxins and undigested food particles to enter the bloodstream, triggering inflammation that affects the brain. Heal the gut, and neurological and psychological conditions improve.
The Three Phases
Introduction Diet
Highly restrictive: bone broth, boiled meats, vegetables. Six stages over weeks to months.
Full GAPS
Expanded but still eliminates grains, potatoes, sugar. Lasts 1.5-2 years minimum.
Reintroduction
Gradual return of restricted foods, one at a time, monitoring for reactions.
What the Science Says
Let's be direct: there are no peer-reviewed clinical trials testing the GAPS diet for autism, ADHD, depression, or any of the conditions it claims to treat. The evidence base consists primarily of anecdotes and Dr Campbell-McBride's own observations.
The Gut-Brain Connection Is Real
The GAPS theory isn't entirely unfounded. Research does show:
- Gut microbiome affects mental health - Studies link gut bacteria to mood and cognition
- Intestinal permeability exists - Though "leaky gut" isn't a recognised medical diagnosis
- Diet influences the microbiome - What we eat shapes our gut bacteria
- Fermented foods may benefit gut health - Some evidence for probiotic benefits
But jumping from "gut health matters" to "this specific diet cures autism" is an enormous leap that the evidence doesn't support.
The Concerning Gaps in GAPS
Key Concerns
- No clinical trials - After 20+ years, no controlled studies
- Dangerous claims - Suggesting diet can treat autism may delay proven interventions
- Nutritional risks - Highly restrictive, especially for children
- Duration - 2+ years is extremely difficult to maintain
- Supplement sales - The GAPS approach includes expensive proprietary supplements
What the Diet Gets Right
Strip away the unproven claims, and some GAPS principles align with evidence-based nutrition:
- Reducing processed foods - Widely recommended for health
- Fermented foods - Emerging evidence for gut health benefits
- Bone broth - Nutritious, though not the cure-all claimed
- Whole foods focus - Less ultra-processed food is generally positive
- Cooking from scratch - Gives you control over ingredients
These elements can be incorporated into any balanced diet without the extreme restrictions or unproven claims.
Risks of the GAPS Diet
Particularly concerning when used for children (as it often is):
- Nutritional deficiencies - Eliminating grains and many vegetables is risky
- Calorie restriction - Children may not get enough energy for growth
- Social isolation - Extreme diets affect family and social eating
- Delayed treatment - Time spent on unproven diets isn't spent on proven interventions
- Disordered eating patterns - Extreme restriction can trigger problematic relationships with food
What to Do Instead
If you're interested in supporting gut health, evidence-based approaches include:
- Diverse plant foods - Variety feeds beneficial bacteria
- Fibre-rich diet - Prebiotics support the microbiome
- Fermented foods - Yogurt, kefir, sauerkraut in moderation
- Reduce ultra-processed foods - Associated with gut health issues
- Consult professionals - Gastroenterologists and registered dietitians
For neurological or psychological conditions, work with specialists who can recommend evidence-based treatments alongside any dietary considerations.
The Bottom Line
The GAPS diet contains some sensible elements - less processed food, more fermented foods, home cooking - wrapped in unproven and potentially dangerous claims. The gut-brain connection is real, but this specific protocol lacks evidence for treating the serious conditions it targets. If you're concerned about gut health, work with qualified professionals rather than following an extreme protocol based on one practitioner's theories.
References
- Cryan, J.F., et al. (2019). The Microbiota-Gut-Brain Axis. Physiological Reviews
- Mari-Bauset, S., et al. (2014). Evidence of the Gluten-Free and Casein-Free Diet in Autism Spectrum Disorders. Journal of Autism and Developmental Disorders
- Sharma, M., et al. (2021). Gut Microbiome and its Role in Autism Spectrum Disorder. Microorganisms
- National Institute for Health and Care Excellence. (2021). Autism spectrum disorder in under 19s: support and management.
