Is is safe to give blood on a diet?

July 11, 2006 9:04 AM

I'm giving blood today. I'm eating 1200 calories per day in an effort to lose a few pounds. Should I eat more to make up for the calories "burned" during donation?
posted by croutonsupafreak to Health & Fitness (12 answers total)

Giving blood for a test, or donating to a blood bank? If your donating to a blood bank, it is possible you will be turned away. They'll ask what you've had to eat so far today. If they don't like your answer, they'll give you a cookie and send you on your way. Giving blood is traumatic; all of a sudden, your body has to replace a lot of red blood cells (and other things). You need plenty of calories in you to be ready. Also, you can't just eat a huge lunch right before giving blood; the calories wouldn't yet be available for use. You should eat a couple largish (or at least larger) meals before donating, and probably one after.
posted by samw at 9:18 AM on July 11, 2006

You should eat a couple largish (or at least larger) meals before donating, and probably one after.

Absolutely.
posted by frogan at 9:25 AM on July 11, 2006

Response by poster: I'm donating blood to the Red Cross.

1200 calories per day is not a starvation diet -- as a woman with a slow metabolism, I burn about 1600 calories per day when I'm not dieting. I had a good-sized bowl of oatmeal with brown sugar for breakfast, I'll be having a sandwich for lunch, a small snack in the afternoon and a healthy dinner.

But I can add a few hundred calories to what I'm planning to eat today if I ought to for health reasons. I'm already expecting to have a cookie and some apple juice. Is that enough?
posted by croutonsupafreak at 9:28 AM on July 11, 2006 [1 favorite]

The Wikipedia article on blood donation says replacing your red blood cell count to previous levels takes about 3-5 weeks after donation. So that 650 kcal number in the OP's AskMefi link is 650 calories expended by the body to replace the lost blood over a span of 3-5 weeks, not all in one go.
posted by junesix at 9:36 AM on July 11, 2006

Well, I'm not a doctor, but that doesn't really sound like enough. I'd do a veggie an cheese omelette with toast or hashbrowns, but I have a pretty fast metabolism. You should call the place you're giving blood and ask them. They know more about it than me.

junesix: you're not eating more just to be able to replace lost blood cells, though. In the mean time, your blood is red-cell-deficient. This can cause fatigue at best, illness at worst. Really, croutonsupafreak, call and ask.
posted by samw at 9:42 AM on July 11, 2006

Huh, I give blood several times a year, and no Red Cross worker has ever asked me what (or whether) I've eaten, only whether I've been drinking water. Then again, I generally look -- ahem -- pretty well-fed.

croutonsupafreak, this is an indirect answer: if your diet is not rich in iron, that could well get you deferred. (My diet is reasonably iron-rich, but I get deferred a couple of times a year when I fail the iron test.) If so, next time, try supplementing with nutrient-dense, iron-rich foods like dark greens, beets, dates, beans, brown rice. I'm now trying to get used to molasses as the sweetener in my coffee or tea, since a tablespoon of molasses has as much iron as a serving of spinach. Mmm, mmm --- iron-y goodness!
posted by Elsa at 9:51 AM on July 11, 2006

Response by poster: Thanks, samw. I'll ask in five minutes when I walk across the parking lot to the blood donation bus. If I ate that much food on a normal non-blood donation day, I'd be gaining weight. My body doesn't handle large quantities of protein very well.

Obviously, if I feel weak or dizzy I'll eat more. Otherwise (depending on what the Red Cross folks say), I'll plan to take in an extra 200 to 300 calories more than planned today.
posted by croutonsupafreak at 9:52 AM on July 11, 2006

Response by poster: Elsa: I have abnormally high iron levels for a vegetarian, according to my doctor. From your list, I've eaten spinach, beets, brown rice and molasses all in the past week.
posted by croutonsupafreak at 9:54 AM on July 11, 2006

(By iron level, I mean hematocrit level.)
posted by Elsa at 9:57 AM on July 11, 2006

So, are you back from the bus yet? Did you faint (I hope not).

I'm with Elsa on the "well-fed" side of the equation and am a male so I've never been deferred for iron. The only time anything went bad was when they missed the vein or something... they got about 7/8's of a bag and couldn't get any more. Usually I gush out my pint in about 5 minutes.
posted by ajpresto at 11:27 AM on July 11, 2006

Response by poster: They said I was fine, just have a couple cookies and apple juice afterwards. Next time I should eat a little extra beforehand, but this time around it didn't matter that much.

The donation did take about 10 minutes longer than normal, and they had to wiggle the needle again to get me flowing again. I don't know if that's related to the diet, or just a random fluke.

So now we know.

Thanks, folks.
posted by croutonsupafreak at 11:32 AM on July 11, 2006

The donation did take about 10 minutes longer than normal, and they had to wiggle the needle again to get me flowing again. I don't know if that's related to the diet, or just a random fluke.

To decrease your donation time in the future (to the extent that you can - some of it is a function of your physiology), drink lots of water. When I gave blood I drank a bunch of water that day and I filled up that bag very quickly. They said it was extremely fast for a first-timer.

Good on you for giving blood, btw!
posted by misskaz at 3:08 PM on July 11, 2006