At the beginning of October, you’ll likely be leaner than you are all year. But don’t celebrate yet, weight watcher! According to a new study from Cornell University, your waist will now begin swelling because of the three-month, heft-inducing holiday season that encompasses Thanksgiving, Halloween, Christmas and New Year’s.

“Everyone gains weight over the holidays -- Americans, Germans, Japanese," says study co-author Dr. Brian Wansink.

To get to this cumbersome conclusion, researchers from Cornell University’s Food and Brand Lab -- an interdisciplinary food psychology and consumer behaviour research facility -- studied the daily weight patterns of 2,924 people in the United States, Germany and Japan over the span of a year.

Across the board, the study’s subjects began packing on the pounds when their respective holiday seasons rolled around. In the U.S., for example, weights began rising around Thanksgiving and peaked around Christmas and New Year’s. It wasn’t until after Easter, some five months later, that weight patterns began evening out.

Germany exhibited a similar pattern, while people in Japan weighed the most during Golden Week -- a major holiday in April.

Moral of the story? If the weight you gain will take five months to lose, perhaps you’re better off watching what you eat now instead of after our quadruple-whammy holiday spree.

“Instead of making a New Year’s Resolution, make an October resolution,” Dr. Wansink says. “It’s easier to avoid holiday pounds altogether than to lose them after they happen.”

You can read the full study online in The New England Journal of Medicine.