It's the time of year when many of us have promised to drink less, eat less and eat better. But a new study shows that in the first few months of the New Year, families may be piling more food into the shopping cart than they do the rest of the year.

"People are making these resolutions and then what we see with [grocery store] purchasing isn't really supporting that," says nutritionist Lizzy Pope, at the University of Vermont and lead author of the study, which appeared in PLOS One in December.

In fact, what she saw was that people bought more food in the months following the holidays than they did while prepping for lavish holiday dinners. During the holidays, people bought, on average, 440 more calories per week than their baseline. But after the holidays, that jumped to a whopping 890 extra calories per week.

Pope and her colleagues at UVM, along with researchers from the University of Ohio and the Cornell Food and Brand Lab, tracked what 207 households bought at a northeastern grocery store for seven months between July 2010 and March 2011. They divided those months into three periods: a baseline for how much and what type of food was normally purchased, between July and Thanksgiving; the holiday period, Thanksgiving to New Year's; and the post-holiday period, January through March.

Unsurprisingly, the researchers found people spent about $16 more than their $106 per week baseline during the holiday period. In particular, people were buying more food around Christmas and that other, highly venerated holiday: Super Bowl Sunday. Of those extra $16, about 75 percent was spent on unhealthy foods.

In the dawn of the New Year, people did spend more on nutritious foods than their belt-unbuckling holiday period – in fact, three times as much. But they were also paying more money per healthy food item, indicating they were buying the more expensive versions of healthy food.

And the households weren't just buying more nutritious food in the post-holiday month, they were buying more food overall. "The calories in their total basket were much higher than any other time of the year," says Pope.

And while a higher percentage of those calories were from healthy food (37 percent), Pope says the total was still shocking. (The title of the study: "New Year's Res-Illusions: Food Shopping in the New Year Competes with Healthy Intentions.")

People seem to be fulfilling their health goals simply by buying the additional healthy items, says Pope — like filling up a shopping cart with cookies and cake and laying a bunch of kale on top of it. She says people think, " 'Of course I'm eating healthy, I have all this kale in my cart,' but there's a deeper level. You feel like you're fulfilling your goals even though you may be sabotaging them."

However, Pope acknowledges there could be outside factors influencing the high calorie purchases in the New Year. Especially in the Northeast where the study took place, people could be stocking up the pantry for winter. The research also didn't look at a full year and she notes that maybe when April rolls around, people buy less calories as they begin to care about what they look like in a bathing suit.

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