Today I’d like to revisit an issue which is becoming a bit of a holiday tradition here at Obesity Panacea. We first reported on this issue in January of 2009, when a number of our colleagues noticed an interesting poster at the local gym throughout the holidays. Despite my post (and an email to the gym’s head office), the poster was back again last year. And so this year I have decided to put up the post preemptively, in the hopes that the misinformation in the poster is not used by any gym chain (or anyone else) this holiday season.
What’s the big deal with this poster? As you can see from the image at the top of this post, the poster contains a picture of an overweight gingerbread, under which it reads “The average person gains 7-10 lbs over the holidays!“. This poster immediately raises a few questions:
1. Where does this information come from? Who is the “average” person they are speaking of? Aged 18-80? Does it include kids? Seniors? Different ethnicities?
2. If the average person gains 7-10 pounds, that means that some people are gaining much more. Is that even physically possible over a 1 or 2 week period (the definition of ‘holiday season’ varies pretty widely from person to person)? Canada has a population of roughly 33 million – if we gained an average of 9 lbs over the holidays, as a nation we are about to put on 297 million lbs this year alone! In the USA, it would mean a collective holiday weight gain of roughly 3 billion lbs!!
This 7-10 lb weight gain statistic seems a bit strange, so I decided to look it up on Google Scholar. Fortunately, I came across an excellent article from the New England Journal of Medicine which examines this very issue. Back in 2000, Yanovsky and colleagues examined the amount of weight gain during the American holiday season (from American Thanksgiving until New Year’s). Then, as now, this claim of 7-10 lbs holiday weight gain was quite common – Yanovsky reports that organizations ranging from CNN to the Texas Medical Association used the information in press releases during the holiday season of that year. In addition, self-report studies tell us that people believe that they gain 5 lbs or more over the holidays, but that does not necessarily mean that they do.
Fortunately, Yanovsky and colleagues objectively measured the body weight of 195 men and women over the course of the year. They report that the average weight gain from mid-November to mid-January was less than 1 lb! Less than 10% of the participants gained 5lbs or more. The weight gain during the holiday season was, however, significantly greater than that during the pre- or post-holiday period, and the holiday weight-gain was not lost over the course of the year.
So, what does this study tell us? First of all, it tells us that the idea that the average person gains large amounts of weight during the holidays is completely untrue. On a somewhat more serious note, the Yanovsky study also tells us that on average, people do gain a small but significant amount of weight over the holidays which is maintained throughout the course of the year. Not enough to warrant fear mongering, but enough to cause some concern – a pound or two a year can add up over time. And some people do experience significant weight gain, a phenomonen which was sigificantly more common in overweight and obese individuals. It is an issue which is worth following, but one that I hope people aren’t losing sleep over.
So remember, as we move deeper into the holiday season, don’t let the gingerbread men (whether on your plate or a poster) get you down. And if you do notice the poster at your gym, please leave a comment below to let us know, and feel free to send them a copy of this post!
Big thanks to our friends Wendy and Geoff Stephen for letting us know about the poster and for their helpful comments.
Yanovski JA, Yanovski SZ, Sovik KN, Nguyen TT, O’Neil PM, & Sebring NG (2000). A prospective study of holiday weight gain. The New England journal of medicine, 342 (12), 861-7 PMID: 10727591