Why, when the calendar turns to a new year and we proclaim our most virtuous intentions to eat right and lose some weight, do we so often fail? A new study finds that come January, our resolve to eat healthfully may run headlong into a runaway train of our own making: a holiday food-buying binge that doesn't end with the holidays but continues to pick up steam well into the new year.
In January, American food shoppers returned to their supermarkets to buy large stocks of healthful foods -- and purchases of that food boosted their weekly food bill more than ninefold over spending seen in the holiday period. But while they were there, shoppers picked up roughly the same quantities of the calorie-rich "special" foods that had boosted their spending, and their calorie intake, during the period between mid-November and January.
The result: Family food shoppers in January more than doubled the calories' worth of food items purchased over the already-bloated levels achieved during the holiday season. And 63% of that average 890-calorie boost in foods purchased (over the pre-November period) came not from nutrient-rich healthful foods, but from foods laden with added fat, calories, sugar and salt.
The authors of the new research suggested that Americans, spurred by family traditions and prospects of shared feasts, begin to escalate their shopping just before Thanksgiving and continue it as Christmas and New Year's arrive. By January -- with football still on TV, a long winter ahead and bathing suit season a distant prospect -- they appear to have established a new status quo, in terms of the money they will spend and the calories they'll buy at the supermarket.
"People are habituated to new baseline purchasing patterns and may have trouble reverting to their early fall, less calorific purchasing," they wrote.
Compared with our July-through-October purchases, the groceries we lug home in January boosted the average calories available to each household member weekly by an average of 890. Food shopping during the holidays began that run-up in calories available per person: During the period between mid-November and the end of December, added food purchases had already boosted the average number of calories available per person by 440 each week.
Instead of throttling back our food purchases, or stocking up largely on healthful foods in the holidays' wake, we seem to double down.
No wonder, then, that the average American gains between three-quarters of a pound and 2 pounds during the holiday season and never seems to take it off. The result is a run-up in weight that we may blame on age and faltering metabolism, but which is, in fact, a testament to the holiday we have packed, literally, under our belts.
To glean these findings, researchers at the University of Vermont, Cornell University's Food and Brand Lab and Ohio State University tracked the grocery-store purchases of about 200 households from July 2010 to March 2011. After recruiting shoppers, researchers had supermarkets supply their subjects' weekly grocery receipts directly, and used the supermarket chain's system of food labeling to distinguish "healthy foods" from those considered "less healthy."
The study was published Tuesday in the journal PLoS One.
What's a post-holiday shopper to do? Recognition comes first, but once you detect the pattern, the study's authors offer a few recommendations: After the holidays, consumers should use written grocery lists to deter impulsive purchases of calorie-laden treats, and substitute as much junk food as possible with fresh produce and nutrient-rich foods. Shoppers could split grocery baskets visually to ensure nutritious foods represent at least half of their purchases.
Leave the cookies, crackers, chips and sodas on the shelves, and fill your cart with whole-grain breads and cereals, fresh fruits and vegetables and sparkling water, said the authors. "The calories will add up slower, and you'll be more likely to meet your resolutions and shed those unwanted pounds," said coauthor Drew Hanks of the Ohio State University, who worked on the study as a postdoctoral researcher at Cornell.