I go for Ambronite - it's real food and 500 kcal makes is perfect for fasting days. Ordered here http://ambronite.com/

5:2 fits my lifestyle perfectly )

Agree! There's also a BBC documentary on intermittent fasting. The idea is to eat just normally 5 days a week, and then two days a week you eat 500 calories if you are a woman, or 600 calories, if you are a man - pretty optimal routine for modern lifestyle :)

I'd rather go for real food, than something that has maltodextrin in it.