I'm doing 5:2, I've learnt lots of stuff from the website and on here. Apart from somewhat over-compensating on "eating" days (meaning weight loss is slow) it's going well, but I'm not being particularly rigorous about when I eat on my fast days, I'm just restricting to 500 cals and having most of them in the evening. Also I may not be fasting for 36 hours, perhaps more like 33 or something. Does that matter? Should I read the book?