I know a book has been written on this - the fast 800 - by Dr Michael Mosley. I haven't followed his recommendations in the book to the letter and his recommended recipes but I still stick to 800 cals daily - since April 14th this year I've started this diet and the results in 4 weeks have been amazing. When I started I was 5ft 1 and around 12 - 12 and a half stone - now I'm around 11st 4. I know I'm still overweight but feel so much fitter. I also run for at least 30 mins every day. My previously tight size 16 clothes feel looser. I had so much difficulty losing weight before- for the past 3 years I've not been able to diet and binge eaten a lot. However, now I've stuck to this for nearly 5 weeks I feel I'm on a roll and determined to keep it going. Has anyone else tried this diet and had similar success?