Last year, I complained that no information was available about the nutritional value of human blood. I was wondering about how to factor a blood donation into my Weight Watchers plan. (Do you get extra points for it, as you do for exercise? If so, how many?) Lo and behold, Cecil Adams has addressed this question in his latest Straight Dope column. Adams cites an article published in the journal Transfusion Medicine that includes an estimate of the caloric value of blood: 600 calories per unit. This means that a unit of blood is equivalent to 12 Weight Watchers points.
For vampires on the Weight Watchers plan, the implications are clear. My daily allotment is 25 points, so a vampire of my body weight would be able to consume two units of blood per day. Since an adult contains about five units, the dieting vampire would not be permitted to drain a human completely. But I suspect they don’t do that anyway; it would take too long. (Vampire lore is wildly inconsistent, so it’s hard to be sure about such things. Has Buffy ever established how often vampires feed, and how much blood they take from a victim?)
I want to emphasize that this is just idle speculation. I know the temptation to put two and two together is considerable, but I am not a vampire. It’s purely a coincidence that my new work schedule only requires me to venture out at night. Greg, Virgil, and Bob can testify that they have seen me in daylight, since I have lunch with them every week.
That reminds me — I need to put sunblock lotion on the grocery list. We’re almost out.