GAPS diet

The GAPS diet or Gut and Psychology Syndrome diet is the core part of the GAPS Nutritional Approach, an alternative medicine approach that aims to reduce symptoms in mental/psychology illnesses such as depression, ADHD and schizophrenia, neurological and developmental conditions including autism, and some neurological disorders including dyslexia and dyspraxia, and some immune or autoimmune illnesses such as allergies and eczema.

The GAPS diet is a considered to be a variant of the Specific Carbohydrate Diet (SCD), but in addition to excluding certain foods it adds in additional foods proposed to have gut healing properties. It aims to reduce inflammation quickly and reduce gut dysbiosis (leaky gut), by using specific foods and supplements to repair the intestinal wall, and using lifestyle changes. The GAPS diet is a very high fat diet that avoids dairy products and is a gluten-free diet.

Theory
The GAPS diet was invented by Natasha Campbell-McBride, a former neurologist and neurosurgeon who trained and practiced in Russia. The GAPS diet was published by Campbell-McBride in her 2004 book, and has not been peer-reviewed. The theory behind the GAPS diet is:
 * The gut is the underlying cause of neurological and psychological illnesses
 * Gut dysbiosis, which Campbell-McBride refers to as abnormal gut flora, is present in neurological and psychological illnesses
 * Treating the gut including gut dysbiosis is the first and most important stage in treating all these conditions
 * Casein proteins (from dairy) and gluten proteins (from cereals) are hypothesized to not be digested properly in the body and to transform to "substances with a similar chemical structure to opiates, like morphine and heroin" which enter the blood-brain barrier and "block certain areas of the brain", causing various neurological and psychological symptoms.

GAPS syndrome
Campbell-McBride groups a wide range of neurological and psychological illnesses and disorders together as "GAPS Syndrome" which she states includes "symptoms of autism, ADHD, ADD, OCD, dyslexia, dyspraxia, schizophrenia, depression, bipolar disorder, sleep disorders, allergies, asthma and eczema in any possible combination". She refers to those affected as "GAPS children and adults" and states that they "fall through the gap in our medical knowledge". These Campbell-McBride also states that anyone with a learning disability should be thoroughly examined for gut dysbiosis.

Evidence
The GAPS diet was published in 2004 but no clinicial trials involving ME/CFS or fibromyalgia patients have been carried out. Very little scientific research has been published about the GAPS diet, and the theory that autism and mental illnesses are caused by gut dysbiosis and gut problems is largely based on Campbell-McBride's personal observations and limited research from the late 1990s, and this theory is not widely accepted.

In 2018, the UK's Advertising Standards Authority (ASA) upheld a complaint about claims on the Bubbling Life website that GAPS Nutrition was effective for chronic fatigue syndrome (CFS), myalgic encephalomyelitis (ME) and anxiety in adults and children, and that also referred to Natasha Campbell-McBride's "research and experience." The ASA upheld the complaint that this was misleading health advertising because Bubbling Life did not provide substantial evidence in response.

Risks and safety
The GAPS diet is a very high fat diet GAPS (60% fat, 21% carbohydrate) and saturated fat intake for an 11 year-old boy exceeds is double the recommendation of no more than 10% of energy intake, and contains only 58% of the recommended calcium intake. Since girls aged 14–18 year have increased nutritional requirements but lower calorie limits than boys of the same age, they have much greater risk of inadequate nutrient intake (malnutrition). The GAPS diet has also been promoted for inflammatory bowel disease (IBD) despite the lack of clinicial trials on its effectiveness and safety, and it was found to be nutritionally inadequate for adult women.

Learn more

 * GAPS Diet website