5 Days of eating what you normally eat (without going too crazy) and 2 days of starvation dieting, eating no more than 600 kcal.
My missus and I are on it - I'm doing it more as a support rather than required. It's also good for exercising your insulin and sugar, supposed to help.
600kcal every Tues and Thurs me us, never at a weekend, because it's horrible, plus, work takes my mind off the hunger. Breakfast was 2 poached eggs and a unbuttered toast. Dinner will be a baked salmon with (lots) brocolli and a light splash of seasame oil.
Get the 5:2 diet book by Dr Michael Mosley
http://www.telegraph.co.uk/lifestyl...-it-help-you-lose-weight-and-live-longer.html