Small Steps Might Curb Weight

Most people could avoid gaining weight simply by reducing the amount they eat by 100 calories a day or burning up 100 more calories daily, according to a new analysis.

James Hill of the University of Colorado Health Sciences Center in Denver and colleagues studied data from the two national surveys of U.S. eating habits and calculated that the prevalence of obesity had increased from 23 percent to 31 percent between 1988 and 1994. If that continues, 39 percent of Americans will be obese by 2008.

On average, Americans are gaining 14 to 16 pounds in eight years, which breaks down to 1.8 to 2.0 pounds each year, the researchers calculated. Each pound is equivalent to about 3,500 calories, the researchers calculated. So to stop gaining weight, it would require most people to reduce their caloric intake or increase their caloric use by about 100 calories a day.

People could walk an extra mile a day to burn that much. Or they could eat less, the equivalent of about three bites of a fast-food hamburger, the researchers said.

"This can be achieved by small changes in behavior, such as 15 minutes per day of walking or eating a few less bites at each meal," the researchers wrote in reporting their findings in the Feb. 7 issue of Science.

Male Seals Spread the Love

Male southern elephant seals, it turns out, are pilgrim playboys on an epic scale. The multi-ton mammals with the trunk-like noses may range as far as 5,000 miles to visit their female harems by powering their way through the icy waters around Antarctica. One bull, nicknamed "Blob," crossed 3,200 miles in a single excursion.

Anna Fabiani, of England's Durham University, and fellow researchers have collected tissue samples from the hind flippers of more than 1,000 unsedated seals in major breeding colonies. In some, the team tracked the animals' nuclear DNA, which is inherited from both parents, and their mitochondrial DNA, which comes from the mother, to analyze the genetic diversity of seal populations.

As the group reports in the current issue of the journal Science, the reproductive reach of just one bull such as Blob has the potential, depending on how active he is, to "homogenize" far-flung populations by spreading his genes far and wide. However, the impact of such male behavior on genetic diversity in the species overall depends in part on how commonly it occurs and in part on other genetic factors.

"It's quite unusual to be able to identify these so-called 'genetic dispersers' " that move from their birthplace and reproduce in a new location, said team member A. Rus Hoelzel, also of Durham University. "Finding one who traveled so far was especially surprising."

Understanding current patterns is important for the seals' conservation, Hoelzel said.

-- Kathy Sawyer

'Mummy's Curse' Debunked

The "Mummy's Curse" has existed as an idea in literature for perhaps 150 years, but nothing gave it a bigger boost than the death in 1923 from a streptococcus infection of George Herbert, Lord Carnarvon, who bankrolled the expedition that opened the tomb of Tutankhamen, the fabled "King Tut."

Media reports jumped all over the story, attributing Herbert's death and the deaths of every living creature anywhere near him to a mysterious malady emanating from the tomb -- the "Mummy's Curse."

Well, it turns out there was no such thing. Writing recently in the British Medical Journal, epidemiologist Mark Nelson, of Australia's Monash University, traced the dates of death of every westerner present at the opening of the tomb and of 11 others who were elsewhere in Egypt at the time.

Nelson found that the 25 people directly exposed to the "Mummy's Curse" lived to an average age of 70.5 years, while those who did not lived to be 75, a difference that is not statistically significant. He investigated only westerners because of uncertainties about the life expectancy of Egyptians at the time.

Nelson said he established dates of death by examining old newspapers, biographical texts and Web-based listings of royals, military personnel and other genealogies. To be "exposed," a person had to have been at the "breaking of the seals" on the third door of Tut's tomb, on Feb. 17, 1923, the opening of the sarcophagus on Feb. 3, 1926, the opening of the coffins on Oct. 10, 1926, or the examination of the mummy on Nov. 11, 1926. In all cases, it didn't matter, Nelson said. Exposure had no measurable effect on survival.

-- Guy Gugliotta

A male southern elephant seal has been documented to swim 3,200 miles through icy Antarctic waters to mate. Understanding these patterns is important for seal conservation.