Sorry, but ... it probably will.
So you spend the holiday season eating and drinking and and exercising only to the extent that eggnog ladles are heavy. And then, come New Year's Day, you compensate: Gym! Yoga! Diet! (And also: Stop procrastinating! Keep in better touch with far-flung loved ones! Finally read War and Peace!)
These goals are well intentioned, designed to make the You of 2013 a slightly better version of the You of 2012. But they will probably fail.
That, at least, according to Google. The firm keeps track of the world's resolution cycle via the web searches it fields from its users. And though searches for "fitness" and "gym" and "diet" are not direct proxies for health-related resolutions, they give a good overall sense of the times of year that find people thinking about those ideas. With that in mind, here are health-related searches from early 2004 to early 2013:
Crazy, right? That is some striking spike-to-dip consistency. Across the search terms, throughout the year, it's peak to dip to drop, at pretty much the exact same rate. Again, this is search info -- so, in the best-case scenario, the patterns here could reflect people's questions being answered early on in the year, with healthful habits being formed and solidified as the months go on. And, hey: maybe! But the much more likely explanation tracks with what we know to be true, so anecdotally that it has become a cliche: that intentions are very different from actions. That whatever we resolve for ourselves at the beginning of the year will likely become a distant memory come the middle of the year -- and even more likely by the end of it.
That doesn't mean your well-intentioned vow to exercise and to diet and to generally be-awesome yourself in 2013 is doomed to failure. But it does mean that your resolve faces challenges. Years' worth of them.