The finding that such a simple action as a daily weigh-in can prevent people from piling on the pounds between Thanksgiving and New Year’s is quite promising. Much of the weight that American adults gain during the winter holidays — an average of 1 to 3 pounds, according to studies — tends to persist afterward, particularly among individuals who are already overweight or obese.
As a result, the winter holidays are known to play a major role in “weight creep” — that insidious increase in weight (about 1 pound per year) that begins in early adulthood.
We’re a long way from the winter holiday season, but not too far away from another holiday season — the Fourth of July — when it’s also easy to overeat. And then there’s summer traveling, which can also wreak havoc with efforts to stick to a healthy diet — and maintain a healthy weight.
How the study was done
For the new study, researchers at the University of Georgia recruited 104 adults, aged 18 to 65. A third of the participants were traditionally aged college students, a fourth were graduate students, and the rest were mostly university faculty, staff or retirees.
At the start of the study — a week before Thanksgiving — all the participants came into the laboratory to have their height, weight, waist circumference, hip circumference and body composition measured.
Half of the participants were then randomly assigned to the study’s “intervention group.” They left the lab with wi-fi (or “smart”) scales, which tracked their weight throughout the study. The scales also provided the participants with graphical feedback on how their weight was fluctuating from day to day.
This group was told to try to keep their weight from going above their pre-holiday baseline number, which was determined by averaging their body weight for the first four days of the study. They were not given any instructions, however, on how to accomplish that goal.
The other participants — the “control group” — were sent home without scales and without being told anything about maintaining their weight over the holiday.
What the study found
The participants were followed through the winter holiday season (Thanksgiving through New Year’s) and then for a 14-week follow-up period. At the end of the study, the daily weigh-in group showed no overall change in weight, while the control group had gained an average of 2.6 pounds.
“Control subjects gained a substantial amount of holiday weight, which coincided with an increase in [total body fat],” the researchers write. “Some of that holiday weight was lost during the follow-up period; however, as a group, they retained almost 57 percent of the weight gain, so that overall weight gain from November to May was significant.”
Interestingly, by the end of the follow-up period, the men in the study’s control group had lost all but 5 percent of the pounds they had gained, while the women had retained 77 percent of theirs.
The study also found that people who were overweight or obese were more susceptible to gaining weight during the study.
Not a sure thing
Daily weigh-ins and subsequent graphical feedback did not entirely protect against weight gain, however. Like the people in the control group, the participants in the intervention group started to gain weight during Thanksgiving week and again in the week leading up to Christmas — a trend that continued through New Year’s Day.
But the intervention group lost weight during the three-week period between Thanksgiving Day and the week before Christmas. That loss helped keep them from ending the study with more pounds than when they started.
The study’s authors believe their findings support something known as discrepancy theories of self-regulation — the idea that to minimize our emotional discomfort, we try to narrow the gap between the actual and ideal representations of ourselves.
“People are really sensitive to discrepancies or differences between their current selves and their standard or goal,” explains Michelle vanDellan, one of the study’s authors and a psychologist at the University of Georgia, in a released statement. “When they see that discrepancy, it tends to lead to behavioral change. Daily self-weighing ends up doing that for people in a really clear way.”
An appealing simplicity
The study comes with several important limitations. The study involved a relatively small group of participants in one geographical location, and it was conducted over a single holiday season. The findings might have been different if they study had been bigger and/or longer.
Also, it’s not clear how “blinded” the participants were to the study’s purposes — or if the fact that the people in the intervention group were motivated to keep from gaining weight because they knew their weigh-in numbers were being assessed by the researchers.
What’s also appealing about the study’s findings is the simplicity of the intervention — daily weigh-ins. “It works really well in the context of busy lives,” says van Dellan. “The idea that people might already have all the resources they need is really appealing.”
FMI: You can read the study in full on Obesity’s website.