The average adult has a blood volume of about 5 liters, or 1.3 gallons, which accounts for about 7 percent of body weight. In regard to folks trying to lose weight, the percentages vary.

Among current top-selling popular diet books is Peter D'Adamo's best-selling "Eat Right for Your Type," in which the naturopathic physician argues that a diet matched to one's specific, evolved blood type — A, B, AB or O — can improve health and reduce the risk of chronic disease. D'Adamo has sold more than 7 million copies.

He hasn't, however, sold researchers at the University of Toronto. They examined 1,455 study participants who provided detailed information about their diet and blood samples to measure health risk factors like cholesterol, insulin and triglycerides.

Their conclusion: While certain "blood-type" diets were associated with favorable effects on some risk factors, the associations were independent of the person's actual blood type. It's possible, said study author Ahmed El-Sohemy, the diets have some efficacy, but he added, "There was just no evidence, one way or the other. It was an intriguing hypothesis so we felt we should put it to the test. We can now be confident in saying that the blood-type diet hypothesis is false."

For would-be dieters who bought D'Adamo's book, that bites.

BODY OF KNOWLEDGE

On average, it takes 72 seconds for a mature human egg to be pushed out of the ovary. The average speed of human sperm is 8 inches per hour. It's estimated that the fastest sperm get to a fallopian tube — and possible conception — in about 30 minutes, though it can happen up to five or so days later since some sperm can survive for up to a week.

NUMBER CRUNCHER

A generous dollop (100 grams) of Marmite, the sticky, brown food paste — think peanut butter — derived from yeast contains 252 calories, 0 from fat. It contains no cholesterol; 4 milligrams of sodium; 24.1 grams of total carbohydrates; 1.1grams of sugar and 38.7 grams of protein.

DOC TALK

Crasher — a person who loses consciousness in an emergency room, often not a patient but a family member who is upset over what's happening with a loved one

PHOBIA OF THE WEEK

Acerophobia — fear of sourness, not the personality but the taste

NEVER SAY DIET

The Major League Eating speed-eating record for sweet corn is 48 ears in 12 minutes, held by Joe LaRue. Warning: Most of these records are held by professional eaters; the rest by people who really should find something better to do.

OBSERVATION

"I went on a diet, swore off drinking and heavy eating, and in fourteen days, I lost two weeks." — American comedian and singer Joe E. Lewis (1902-1971)

CURTAIN CALLS

Hans Steininger, the burgomaster of Braunau, Austria, died in 1567 when he broke his neck by tripping over his own beard. The beard measured four-and-a-half feet long and was usually kept safely tucked away in a leather pouch.

To find out more about Scott LaFee and read features by other Creators Syndicate writers and cartoonists, visit the Creators Syndicate website at www.creators.com.