Centuries before the world obsessed over the sudden weight loss of Lindsay Lohan and Mary Kate Olsen, there was William the Conqueror, who apparently got so fat he had trouble staying on his horse.
In the years after his triumph at the Battle of Hastings, the French royal grew so rotund that he devised his own weight-loss technique: He confined himself to his room and consumed nothing but alcohol.
Poor William subsequently died of abdominal injuries in 1087, when he fell from his saddle at the Siege of Mantes. He was so obese, clergy had trouble fitting him into his stone sarcophagus, and the stench of his body filled the chapel with a foul smell.
At least his horse must've felt some relief.
Nearly a millennium later, humanity is still vexed by fad dieting, forever searching for that painfree formula for slimming down. While there's a general consensus about the basic rule of the metabolism -- that the calories you burn must exceed the calories you consume -- achieving that goal is up for debate. And of course, a new diet scheme comes out all the time.
One minute diet gurus are saying, "Eat no carbohydrates." Then it's "Watch your fats." Just when you think the Atkins and South Beach diets are here to stay, the Sonoma Diet comes along.
And what of the diets of yesteryear? The Scarsdale Diet, the Cabbage Soup Diet, the Astronaut's Diet, the F-Plan and the Zone have all come in and out of fashion, and some people still swear by them.
Remember back in 1988, when Oprah Winfrey dragged a wagon piled with 67 pounds of fat before her audience, announcing she had lost that much with Optifast? Later, she became an advocate for good eating and portion control.
Celebrities can offer the worst weight-loss examples. In the mid-1970s, when Elvis Presley was squeezing into those white jumpsuits, he had reportedly tried the "Sleeping Beauty Diet" in which he was heavily sedated for several days, hoping to wake up thinner.
Sadly, the King's waistline was overwhelmed by his famed weakness for peanut-butter-and-banana sandwiches deep fried in butter.
In the last 25 years, it seems we've seen it all: Vision-Dieter Glasses to make food look less appealing; The Mini-Fork system to help people take smaller bites; even a cultish group called the Breatharians, who claimed that ancient yoga practices could remove the need for eating altogether.
Then there are books, some with titles like "The Three-Week Trance Diet," "The Blood Type Diet Encyclopedia" and "More of Jesus, Less of Me," that have sparked endless debate in the diet world.
"One thing you'll always see is that people are always looking for magic, and they're surprised when you tell them otherwise," says Dr. Sanford Siegal, a Miami diet book author who has treated obesity for 40 years.
"Many of the new diet schemes today are actually just warmed-over fads from yesteryear, but people still want to believe."
Many believe that dieting is a relatively new phenomenon. Up until the 20th century, food was so scarce that corpulence was a sign of affluence. The Fat Man's Club of Connecticut -- once a proud group of businessmen -- didn't close its extra-wide doors until 1903.
1903 might have marked a turning point in fat status. It was that year that 355-pound President William Howard Taft -- the most well-rounded commander in chief in history -- got stuck in the White House bathtub and vowed to reduce.