That 5-pound statistic is bloated by 4 pounds

Open magazines this time of the year, and there, splayed across the pages, is an oft-repeated warning: Between now and the new year, we are all doomed to gain 5 pounds or more from excess consumption of all that pie, meat, stuffing, yams, cookies and sweetmeats. But despite a dearth of data -- holiday weight gain is not the best-studied topic in medicine -- experts have enough stats to say that this number is overblown for most people. That doesn’t mean health professionals are unconcerned. “It’s sort of a good news, bad news kind of thing,” says Dr. Jack Yanovski, head of the Unit on Growth and Obesity at the National Institutes of Health in Bethesda, Md.

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According to several 25-year-old surveys, many people believe they put on at least 5 pounds over the winter. News media repeat the assertion without offering a credible source. In 2000, Yanovski and colleagues decided to examine the truth behind the claim.

To do so, they weighed 195 individuals four times during the holiday season. Half of the people in the study were of normal weight, with a body mass index (BMI) under 25, while the other were overweight or obese, with BMIs of 25 and above, or 30 and above, respectively. The volunteers believed only their vital signs were being monitored.

They reported in the New England Journal of Medicine that, on average, the study volunteers gained only about 0.4 kilograms (eight-tenths of a pound) between mid-November and mid-January. That was the good news. The bad was that they lost less than 0.1 kilograms (about one-sixth of a pound) by spring. In fact, starting from a pre-holiday point in late September to spring, people gained about 1 pound.

Gaining a pound each holiday season will contribute to the overall weight gain seen in adulthood, Yanovski says.

More bad news: Averages hide the fact that some people are gaining a lot more weight than others. Fourteen percent of the overweight and obese group gained more than 5 pounds each.Yanovski’s results are consistent with another study conducted by exercise physiologist Holly Hull of the University of Oklahoma Health Sciences Center in Oklahoma City. Her study, reported at the annual meeting of the Obesity Society in October, followed the weight of 94 college students as they made their way through all the turkey legs, candied yams and apple pies. The students were weighed before and after Thanksgiving -- and, over 12 days, they gained an average 0.9 kilograms, or nine-tenths of a pound.

Although this number is far below the tossed-around “5 pounds” statistic, Hull was disturbed by the change in body composition she found when the study was continued past the new year. She and her co-workers scanned 84 of the students with X-rays to determine the fat and muscle content of their bodies. Though their average body weight returned to pre-turkey day levels by January, their overall body fat rose by 1.5%. In other words, “they lost muscle and gained fat,” Hull says. Fat they get to squish into their new Christmas clothes as tokens of an overly happy holiday season.

A third study, sponsored by a supplement company and published in August in the peer-reviewed International Journal of Obesity, found that overweight individuals gained more than that pound -- but also suggested a way that might help stave weight gain.

Nutritional scientist Dale Schoeller of the University of Wisconsin-Madison tested whether the food supplement conjugated linoleic acid (CLA) could prevent weight gain during the course of a six-month study. Twenty overweight individuals whose diets were CLA-free gained about 2.4 pounds during the holiday period. But another 20 who consumed about 3 grams of CLA for six months held steady.

Schoeller warns, though: “CLA is not a magic bullet that overpowers the diet.” Unlike that whipped cream-laden double chiffon pie.

Mary Beckman