I've also been trying out the 5:2 diet. Yes, I know it's a fad, but I've been on it 3 weeks and boy is it working for me!
For those who have no idea what I'm talking about the diet works thus: for five days out of seven you eat normally, for two days you "fast" which for ladies means 500 calories and for gents 600. Those two days must not be consecutive.
From Wikipedia (5:2 diet) Studies conducted by the Baltimore National Institute on Aging reveal that fasting once or twice a week lowers Insulin-like growth factor 1 - IGF-1 levels, which encourages fat burning ...
So I'm assuming that's how it works.
It's actually a really easy diet to stick to for me which is what I am finding so good about it. Because you can eat normally the rest of the time (and I mean normal, not pigging out all the time) rather than thinking, can I have this, can I have that, it is so easy to maintain. My fast days are Monday and Thursday and so far I haven't even been tempted to cheat.
What I have found it that vegetables are my friend (which has probably improved my diet to be fair) and I have invested in a variety of herbal teas because they have negligible calories, but give my taste buds something to enjoy during the day that isn't always the same. Morrisons NuMe range also have some amazing soups - the spicy parsnip and apple is stunningly good. I've never really found a low fat range of anything I liked before, usually low fat = tastes like crap, but those soups are brilliant.
I don't believe in scales or that everyone should be a matchstick, I believe in feeling good about myself and having clothes that fit, so I've no idea what weight I have lost so far, just that several bits of me are much smaller than they used to be. I am exercising as well, which I slacked off doing during Dec, but I was doing the same exercises all last year and they never had such a significant effect before. I've actually been really surprised by the results. The whole slacking off during Dec was actually why I thought about dieting at all; too many choccies and not enough exercise made me somewhat rounder than I wished to be. My ankles are already thanking me.
Rob's doing the diet too because he wanted to lose his belly and his trousers are now all too big and his tummy is almost gone (bastard! - the male metabolism is so unfair).
Anyway, I have no idea if it will keep working or if it is my metabolism going, well isn't this strange, but I shall keep going and find out. I have read good things about this diet and bad things, but so far I feel better for it. If I start feeling not better for it I will stop :).