He is well known for his disputed research into dietary therapy and autism, having claimed that autistic children may have a "leaky gut" which allows certain peptides to enter the bloodstream, and claimed that they excrete unusually high levels thereof.
As a result of this speculation, he has promoted the use of a gluten-free, casein-free diet to ameliorate the symptoms of autism, a theory he developed along with Kalle Reichelt.
In addition, he has claimed that a protein found in milk may play a role in the etiology of autism.
[3] In addition, this survey concluded that one in ten parents of autistic children attributed their child's autism to this vaccine, and that these children had much higher levels of urinary indolyl-3-acryloylglycine.
[7] In 1980 Shattock helped raise £80,000 to pay for the North East Autism Society (NEAS) centre at Thornhill Park, when he was known as "the Birdman".