The FastDay Forum

Hi, I'm due to give blood next week - we're always told to eat well on a donation day, but does anyone know if I'd be able to fast the day after?

Thanks in advance for any advice.

Good question. I often give blood but didn't think of this. I would say try to have enough time between giving blood and fasting but as long as you have drunk enough water and eaten well on the blood giving day, it should be ok. I don't exercise when I have given blood, but the next day is ok.

Let us know ow you get on

Advice from Michael Mosley is probably best not to give blood on a fasting day. I didn't ask but the day after should be fine as your blood should be replenished by then.

I reguarly give blood and use it as an excuse to eat loads - so I definitely wouldn't go on a fast day!! Thankfully our donation days are usually a Saturday so there would be no chance of that anyway!!

I would probably be fine to fast the day after a donation but personally, I wouldn't fast the day before. I sometimes get a bit light-headed the morning after a fast day a wouldn't want to pass out or anything.

Drew, when you say replenished if you are meaning your body will have made new blood to replace that which you donated after a day or so I think you are wrong. My understanding is it takes 4-6weeks to make up what you donated, hence the period you have to wait before making your next donation.

Forgot to add it's a 4-6 week period unless you are on a cycling team with Lance Armstrong

Thanks for all the replies. I'm due to donate next Wednesday, and planning to fast on Monday and Thursday, though I'll see how I feel on Thursday morning, will let you know how things go.

jem13 - it's also my excuse to eat lots on a donation day!

skippyscuffleton wrote: Drew, when you say replenished if you are meaning your body will have made new blood to replace that which you donated after a day or so I think you are wrong. My understanding is it takes 4-6weeks to make up what you donated, hence the period you have to wait before making your next donation.

You are correct in that it take 4-8 weeks for red blood cells to be replaced, volume will recover in 24 hours.

Hi, just a quick up date - I fasted Monday, donated Wednesday (eating lots!) and have been fasting today (Thursday) with no problems.

That's useful to know, thanks Egduf!

Hi, all went fine yesterday, so would have no problem in future with fasting the day after donating.

After a bit of advice, having read through the above post - I am due to have a fast day tomorrow and to give blood on Tuesday afternoon - do you think I'm ok to do this? My son and I usually have a good lunch of jacket potato and beans on a Tuesday!

Thank you x