If you're worried about overeating during the holidays, here's some good news: Most people don't really gain much weight this time of year.

Now the bad news: Even a small amount of holiday weight gain is probably going to stay with you a lifetime.

Although it has been widely asserted that people pack on five to 10 pounds during the holiday season, research shows that holiday weight gain has been greatly exaggerated. Not only have media and even some medical reports overstated how much weight people tend to gain during the holidays, but individuals themselves also think the problem is worse than it is.

In surveys, healthy people report that they gain, on average, more than five pounds in the fall and winter. But research shows most people gain only about a pound or two. In March 2000, the New England Journal of Medicine reported on a National Institutes of Health study of nearly 200 adults, tracking their weight over the course of a year. During the pre-holiday period from early October to mid-November, the subjects on average gained less than half a pound. During the heavy eating period between Thanksgiving and New Year's, the average person gained a little less than one pound. But after the holidays they lost nearly three ounces by the time they were weighed in early March.

That put the net total weight gain for the holidays at just 1.06 pounds.

To be sure, the study group may have been more health conscious than the general population, and some people will gain more over the holidays. In particular, people who already are overweight are more likely to pack on more extra pounds during the holidays. In the NEJM study, people who were overweight or obese gained an average of about five pounds.

But the greater concern in the study was that the small amount of weight the participants gained during the holidays never came off. Study participants who came back to be weighed the following fall weighed on average, about 1.5 pounds more than they had in the previous year.

This shows that while the study members had gained a little weight the rest of the year, the bulk of their annual weight gain was packed on during the holidays. Even though 1.5 pounds doesn't sound like much, over the course of a decade it amounts to 15 extra pounds. The data are consistent with other research that show the average annual weight gain is one-half pound to nearly two pounds.

The important message to take away from all this data is this: If you focus on controlling your weight during the six-week holiday period, you can make a significant dent in your annual weight control efforts in a very short time. That doesn't mean you should diet during the holidays. It simply means you should to do a better job managing and monitoring your weight.

The problem is, many people don't worry much about a pound gained over the holidays because they think they've beaten the odds. Even the New England Journal study participants guessed wrong about their own weight gain -- thinking they'd gained almost four pounds instead of just one.

"I think all the hype about holiday weight gain helps people to rationalize that it is OK to just cave in," says New York University nutritionist Lisa Young.

Losing weight is a lot tougher than gaining it. It takes no time to scarf down 3,500 more calories than you need, which adds a pound. But it can take weeks to shave 3,500 calories from an 1,800-calorie-a-day diet. The human body evolved to pack on pounds to protect it in times of food shortages, but there is no apparent biological mechanism for losing weight.

While many people opt to indulge during the holidays with the promise of healthier living in the New Year, other research indicates that's the wrong approach. Studies suggest that if you know you are facing a diet in the future, you will likely binge before the diet starts.

A recent study of dieters who lost weight and kept it off showed that consistency is what counts. Last year, the International Journal of Obesity reported that people who manage their weight the best are those who eat the same whether it's the week, weekend, vacation or holiday season. Consistent eaters are nearly twice as likely to keep weight off as eaters who allow themselves to indulge on weekends or holidays and go back to strict eating during the week or after the holidays.

Another report in the medical journal the Lancet suggested the reasons we are so vulnerable to weight gain around the December holidays may be due in part to snacking and the fact that there typically is more food sitting around than during other times of year. The report cited research that showed snacking during the day didn't change how much food study participants ate at dinner, suggesting that we are conditioned to eat certain amounts at mealtime, regardless of what else we've consumed. Snacks between meals don't send our body the same satiety signals, so calories consumed in snacks tend to be above and beyond what we need.

It also makes sense to weigh yourself more often during the holidays, to make sure you're not overdoing it. And Dr. Young says it's not the time of year to try to lose weight -- your effort should be on not gaining weight.

"Don't let the first episode of overeating at a party be a license to overeat every day all the time between Thanksgiving and New Year's," Dr. Young says.