For the average person, the time just before the start of the holiday season is the low point in an annual weight gain pattern, said the researchers who analysed the wireless weigh-ins of nearly 3,000 individuals in three countries.
"Everyone gains weight over the holidays -- Americans, Germans, Japanese," said Brian Wansink, Director of Food and Brand Lab at Cornell University, at New York in the US.
But, he said, an annual holiday ritual repeated at the start of the season could go a long way.
"Instead of making a New Year's resolution, make an October resolution," Wansink said.
"It's easier to avoid holiday pounds than to lose them after they happen," he pointed out.
In the US, weight patterns begin rising at Thanksgiving and peak around Christmas and New Year's.
"We found that in the US, it isn't until after Easter, about a five-month period, that weight patterns even out," Wansink said.
The trend among the 1,781 American participants indicated a weight bump of 0.2 per cent during Thanksgiving, and another 0.4 per cent at Christmas.
It takes about five months to lose those holiday pounds, with weights typically stabilising from May to November before the cycle begins anew, the study, published in the New England Journal of Medicine, said.
Wansink and his colleagues from Tampere University of Technology of Finland used scales that sent data over a Wi-Fi connection rather than requiring participants to self-report or visit a testing site for weigh-ins.
The researchers also analysed yearly weight patterns of 760 German and 383 Japanese participants.
Similar to their American counterparts, those in Germany weigh the most around Christmas, while those in Japan weigh the most during Golden Week, four major holidays in the spring.
Each country also showed a peak in weight gain at New Year's.
