The FastDay Forum

I've noticed a real deterioration in my sleep quality on fast days since I started 5:2 at the beginning of the month.

I've been tracking my sleep for about 4 years on my iPhone, using an app called Sleep Cycle, as I've suffered from intermittent insomnia for more than 30 years. On a good night I'll get 6-6.5 hours and average somewhere between 70% and 85% sleep quality.

On the days when I've fasted my sleep quality has plummeted to 50-60% and I'm averaging only 4.5-5 hours. Significantly, my sleep on these nights consists of long periods of sleep so deep I'm almost comatose, interspersed with periods of total wakefulness. I'm not getting that vital REM sleep so I'm waking exhausted and headachey.

Ironically, on normal days I'm still getting my REM sleep even when I've had several large glasses of wine in the evening.

This is my main downside so far.

It's-interesting I find I sleep so soundly too that I know I haven't moved. Other time I am as bright as a button and sleep won't come. You seem pretty up on the nature of sleep eg REM. maybe the nerdy corner might have done some good threads on sleep and what is happening for you or not

Sweet dreams - reminds me I seem to be recalling my dreams less

I've not suffered from this, but a lot of others have. Some seem to find that eating later on a fast day or having a little food before bed has helped. I tend to eat at about 9pm on fast days just because I normally play football on those evenings. This might have helped me?

Ah, I feel for you. I have lost my sleep together with the weight with 5:2. I only sleep when I take a pill or when I've been out drinking.
Yesterday I slept after 4am and the day before after 6. Saturday was a good day after a few pints and lots of pizza. They knocked me down for a good 8 hours, bliss...

I wish I could tell you that it will go away, hey, perhaps it will although in my experience, it gets worse with time.

I think I've had almost every side effect of 5:2 -except for being cold but I started in spring- and yet I wouldn't change it for the world!

I fasted yesterday and had my main meal around 9pm. I was pretty full by then even though I'd had only 220 cals all day. However, I attacked the fruit bowl at around 10pm, as I noticed my mango and some figs were about to go overripe (and most annoyed that I had to chuck some unsalvageable nectarines), taking me to 450 cals. Went to bed at around 11.30, lights off at 12.30 (quite late for me). Was absolutely spark out, no dreams, until 4am, then deep asleep again for another hour until I woke at 5am and got up. I do often eat late and 10.30-11.30pm is my usual lights out period, while I'm normally up at 6ish.

Yes, it seems quite a few of us suffer from this "alert wakefulness", I do and it is a pain. I have tried magnesium supplementation and various other things with inconclusive results. It seems to affect women more than men but I have decided a sex change would be a step too far in my search for a solution!
If you do find anything that helps please post about it!

I will. I think I'm going to have to do a little digging when I have a free moment. And, as gillymary suggested above, post in the nerds' forum for some science!