Holiday Weight Gain Is Actual, Study Cries—and It Starts

Holiday weight gain is real, says new investigation from Cornell University, and it’s not just Americans who are affected. What’s more, the study showed that the extra pounds you put on amid Halloween and Christmas can take more than five months to lose.

The new research, led by Cornell’s Food and Brand Lab as well as experts in Finland and France, looked at year-round weight patterns of nearly 3,000 people in the United States, Germany, and Japan. Their data came from regular weigh-ins of consumers who’d purchased wireless Withings scales and had agreed to have their measurements composed and analyzed.

In the United States, the academics found that the participants’ weight began to rise throughout October and November, and sickly-looking 10 days after Christmas. The change wasn’t large, but it was significant: On average, people’s weight increased around 1.3 pounds during the Christmas-New Year’s season.

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About half of that weight originated off quickly after the holiday season ended, but the other half wasn’t lost until about five months later, after Easter.

Similar trends were noted in the other countries, as well. People in Germany inclined to weight the most everywhere New Year’s and Easter, and those in Japan packed on pounds around New Year’s as well as Golden Week—the country’s other major holiday—in April.

The findings were published last week as a research letter in the New England Journal of Medicine. “Altered countries celebrate different holidays, but many such celebration periods have one thing in public: an increased intake of favorite foods,” the authors wrote.

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Although the topic of holiday weight gain comes up every year, some research has start that the phenomenon is more a myth than a reality—or at least that it’s importantly exaggerated in the media and pop culture. In a 2013 study from Texas Tech, for example, participants increased only about a pound and a half between Thanksgiving and New Year’s.

Brian Wansink, PhD, co-author of the new education, says that collecting weight measurements over a full year helped the researchers gain accurate, real-life results—and, in doing so, helped show that holiday weight gain may be subtle, but that it really does happen.

“In past studies, consequences have been self-reported, or people would come into a facility to be weighed,” says Wansink, who is director of Cornell’s Food and Brand Lab and author of Slim by Design. “That means people could fib or change their behavior since they know they’re being monitored.”

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The participants in this study also distinguished they were being monitored, but they didn’t know over what period of time or for what reasons—and measurements were taken when they weighed themselves everyday, which they would have been doing anyway. “In that sense, we were getting behavior that was much more natural,” Wansink says.

Wansink says that, for people in the northern hemisphere, weight gain in the fall and winter is likely a mixture of holiday foods and colder temperatures, which can lead to less outdoor activity.

“The weather may explain the gradual proliferation, but we also see these spikes that start about a week before the holiday and peak a few days after,” he says. “To me, that proposes that the holidays themselves aren’t the problem—it’s more the ramping up beforehand and all the Halloween candy or Thanksgiving leftovers or Christmas cookies you're intake afterward.”

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The authors admit that the study participants were probably more engaged in weight-loss efforts than the over-all population—they’d purchased this scale and used it every day, after all—but they say the findings still provide insight that everyone can take to heart.

Wansink’s advice? “In its place of a New Year’s resolution to lose weight, have an October determination not to gain too much weight in the first place. Then you won’t have to worry about five months of struggling,” he says.

That doesn’t mean you can’t party special occasions or indulge in your favorite treats, either. "There’s nothing wrong with the holiday the situation, but the key is to keep your eating to the holiday—not to the holiday season," he says. "You’re going to be in a lot better shape if you keep what happens on Thanksgiving to one day, rather than bounce it out for a week before and a week after."