David Perlmutter is an American researcher, author, and physician. He is president of the Perlmutter Health Centre, and is known for his functional and holistic approach towards treating brain disorders. Perlmutter wrote Grain Brain, which urges to people to eat more fats to avoid excessive grains and gluten, as he believes gluten causes neurological conditions. He is a medical advisor on The Dr Oz Show, and has contributed to the Huffington Post.