'Tis the season when we'll see countless articles about holiday weight gain. It's commonly believed that Americans gain, on average, 5-10 pounds between Thanksgiving and New Year's. It turns out that the average gain is closer to 1 pound. But that, according to a study, is a pound you never lose.

And there is something you should keep in mind about that pound. After a few decades that annual pound becomes obesity.

But say you're someone who does gain a few pounds this time of year. Is it really because you eat turkey, mashed potatoes, fruitcake, and eggnog nonstop from late November to Jan. 1? The truth is, there are other things going on too.

Certain psychological factors, and not just the increased availability of rich foods, may contribute to holiday weight gain. One main factor is stress.

In several studies, financial, family and work stress were associated with increased weight gain over time. Some of that gain may by due to stress-induced overeating. So rushing around the mall piling up credit card debt may be just as fattening as pumpkin pie.

Another culprit to all of this is lack of sleep. For many people, this is a busy time of year and it's tempting to squeeze more hours out of the day by staying up later. But, as recent research suggests, sleep deprivation can contribute to weight gain.

This holiday season, try to not get stressed out and make sure to get plenty of rest. For me, my goal is to not have to update my wardrobe because of waist size.