You can be referred to a professional dietician on the NHS. It's free. They have full access to your medical records. They know you and your circumstances intimately. Whether you like or do what they tell you is a different kettle of fish. I have no doubt at all that Mosely is very good and he is a medical professional but he doesn't know you and no single diet is suitable for all circumstances. Follow his advice by all means but make sure you see your own doctor or dietician regularly. I have lost 4 stone so far with WW but I also saw a dietician in the early days and always check with my doctor if I want to make any drastic changes in my lifestyle.