Clean Eating – The Dirty Truth

9PM, BBC2 Gluten-free, grain-free, alkaline-based… The latest diet craze is ‘clean eating’, with advocates claiming it can make you feel better and healthier. But what exactly is it? Does it work? Is it really good for us, or is it dangerous pseudoscience that encourages an obsessive relationship with food? Dr Giles Yeo investigates for Horizon.