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Can I donate blood to lose weight?

Dear Cecil:

OK, so I'm trying to lose some weight. My current plan, eat less and exercise more, is working pretty well, but I want to take it up a notch. So I'm wondering: How many calories are in a pint of blood? How often can you donate without making yourself ill? This could be a great thing for both humanity and myself.

ubernina from Wisconsin

Illustration by Slug Signorino

Cecil replies:

Americans are so pathetic. A while back I heard from a guy who reasoned that: (1) beer is cold; (2) when I drink beer, my body warms it up to 98.6 degrees; (3) this burns calories; (4) therefore, drinking beer helps me stay thin. Then there was the genius who argued: (1) fat people carry more weight; (2) carrying more weight means doing more work; (3) work = exercise; (4) therefore, fat = good.

Your proposal continues this dubious tradition. Presumed advantages: (1) You get to lie on a couch! (2) You get to watch TV! (3) You get to eat Oreos and drink juice! The only disadvantages: (1) You have to tell a complete stranger whether you’ve accepted money or drugs for sex; (2) needles; (3) they drain the blood out of your body. OK, not all the blood, but that’s what it would take for this stupid plan to work.

Don’t get me wrong. Blood donation is a noble thing. Your columnist, not content to devote his intellect to global improvement, regularly contributes a pint of his blood too. But I don’t kid myself that I’m going to lose weight this way.

A glance at the medical literature might lead you to think otherwise. In the October 2001 issue of Transfusion Medicine we find an article entitled “Six Hundred Reasons to Donate Blood” by D.A. Redelmeier. This closely reasoned treatise consists of two paragraphs. The first notes the disadvantages of blood donation, e.g., “Some risk of financial cost is assumed if sloppy application of the disinfectant causes a bad clothing stain.” The second paragraph provides the following analysis:

“Perhaps blood donation could be promoted as one way to lose a bit of unwanted weight. Taking into account the composition and energy in each component … I estimated that one unit of blood reflects about 600 cal of food intake. Hence, a single donation can off-set either 2 hamburgers, 3 donuts, or 5 granola bars. Awareness of these statistics might increase the appeal of blood donation, particularly among healthy adults who are concerned about obesity.”

Very droll, doc. But let’s quit the kidding. According to the American Red Cross, “People in good health who weigh at least 110 pounds can donate a unit of blood as often as every eight weeks.” That means you can donate about six times per year. One pound of body weight equals 3,500 calories. So if we accept Redelmeier’s calculations, and you donate the maximum safe quantity of blood, and you eat and exercise just enough that otherwise you’d maintain your original weight, you’ll lose roughly one pound per year. Large charge.

Everybody’s a critic

Dear Cecil:

I was wondering what is the point of having an illustrator if he doesn’t illustrate some of the concepts that Cecil is trying to explain to the Teeming Millions? Especially when it comes to the more technical explanations that are hard to visualize. Other sites like kick your butt when it comes to things like that, they have 3-D animations and video clips and everything. Although they don’t have any of the humor or style of Cecil Adams, plus the site is way more commercialized than Straight Dope. I don’t expect the Straight Dope to be a library or encyclopedia when it comes to stuff like that, but it is a fountain of knowledge and I think if you are fighting ignorance you should do it right. I can appreciate how a comedic cartoon can complement Cecil’s brand of humor, and I mean no offense to Slug, but I still want more.

— Galo

Cecil replies:

Hush, cretin. Most weeks I’m dazzled by Slug’s artistic vision. But I’ll admit: there are times when I’d kill for a nice pie chart.

Cecil Adams

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