As with all growing religions, you know it by its disciples. On The Great British Bake Off, one contestant, Ugne Bubnaityte, has denounced cake as a ‘nutritional sin’ and she hopes to win with low-fat, vegan and gluten-free recipes. Commercially, she’s on to a winner: the market for gluten-free food is soaring and is forecast to grow by 46 per cent, to £560 million, within two years. For those who can’t wait, there’s always the NHS, which wrote 211,200 prescriptions for low-protein or gluten-free food last year (including cakes and pizza). As Dr James Cave, editor of the Drugs & Therapeutics Bulletin, puts it, the NHS is ‘acting as bakers and grocers