Weighing yourself daily on a bathroom scale and tracking the results on a chart may help you both lose weight and keep it off — particularly if you’re a man, according to a new study published in the Journal of Obesity.
The strategy appears to work because it is so simple — and visual, said Carly Pacanowski, a post-doctoral researcher at the University of Minnesota’s School of Public Health, in an interview Thursday with MinnPost. Paconowski co-authored the study with David Levitsky, a professor of nutrition and human ecology at Cornell University in Ithaca, NY, where she received her PhD.
“This is something that people can do habitually, like brushing their teeth,” Pacanowski said. “It’s particularly useful in catching weight gain before it creeps up 10 pounds or 20 pounds. And we know that preventing weight gain is easier than losing weight.”
For the study Pacanowski and Levitsky randomly assigned 162 overweight volunteers to either an “intervention” or a “control” group. The average age of the participants was 46, and the average body-mass index (BMI) was 33.5. Most were women and white.
Both groups were asked to lose 1 percent of their weight in whatever way they wanted. (For most of us, dropping that amount of weight requires eliminating about 150 calories daily from our diet for two weeks.)
All the participants attended a single educational session in which different tactics for losing weight were described. These tactics emphasized making small changes, such as skipping dessert a few times a week or switching to a lower-calorie meal at lunch. People were instructed to try whatever method of losing weight they thought would work best for them.
The intervention group was also given a bathroom scale and asked to weigh themselves first thing in the morning. They were then asked to record their weight on a designated website, which would translate the information into a graph so each participant could follow his or her individual weight-loss progress.
The people in the control group were shown how to track their weight, but they were not given any specific tools to do so. Once a person in the intervention group lost 1 percent of his or her weight — and kept that weight off for 10 days — the program gave them a new target to lose another 1 percent. The process was then repeated until the participants lost 10 percent of their starting weight.
After a year, the people in the control group were provided with a bathroom scale and access to the weight-tracking website. Meanwhile, the people in the initial intervention group were told to continue tracking their weight to either lose more weight or maintain the weight loss they had already achieved.
At the end of two years, the data from all the participants was analyzed. Pacanowski and Levitsky found that the daily weighing-and-tracking intervention program had a small but significant effect on weight loss.
People in the intervention group lost an average of 2.7 percent of their body weight during the first year, while those in the control group lost an average of 0.5 percent.
During the second year, the members of the control group — which had now become an intervention group — lost an average of 1.9 percent of their body weight.
Surprisingly, however, the increase in weight loss was statistically significant only among overweight men. Women in the intervention group did get leaner, but they did not shed many more pounds, on average, than women in the control group.
“It is possible that the sample size was too small to detect a significant between-group effect or that this method was simply not effective beyond what women normally would do to lose weight,” write Pacanowski and Levitsky.
“For males,” they add, “the contrast is clearer — males in the control group gained weight over the first year while males in the experimental group lost weight.”
Very few of the study’s participants reached the 10 percent weight-loss goal. Of those who did, six (8.6 percent) were in the intervention group and three (4.6 percent) were in the control group.
Twenty (28.6 percent) of the intervention group participants and seven (10.8 percent) of those in the control group lost 5 percent or more of their weight during the first year.
Those numbers are low, so a strategy that relies only on frequent weighing and tracking may not be sufficient to help many people shed a lot of pounds.
But the second-year data of this study revealed an important finding: The average weight gain during that “maintenance” year was essentially zero.
That’s remarkable, given that other research has shown that within a year of ending any kind of weight-loss program, most people gain back, on average, about 35 percent of the pounds they just shed.
“Weight regain is a big problem,” said Pacanowski. The study’s findings suggest, she added, that daily weighing may be more beneficial in preventing weight regain — or in keeping people from putting on excess pounds as they age — than in losing weight.
Limitations and implications
As Pacanowski and Levitsky point out, their study has several limitations. To begin with, it involved a small and fairly heterogeneous group of participants. It’s not clear, therefore, if the study’s findings are applicable to other populations.
It’s also not clear how much the participants’ efforts to lose weight was influenced by knowing their progress was being observed online by the researchers.
Still, the study suggests that a low-cost, easy-to-implement weigh-and-track intervention — which almost everybody can do with a bathroom scale and an Excel spreadsheet — may be useful in helping some people reach and maintain a more healthful weight.
The study also calls into question a long-standing piece of advice often offered to people trying to lose weight: that they should weigh themselves no more than once a week.
“That’s a big controversy,” said Pacanowski. “It’s not like there is an empirical basis for saying you should weigh only once a week.”
Paconowski isn’t ready to say that this new study resolves that controversy. “But one participant in this study told me that for her, [weighing daily] actually demystifies the scale,” she said. “It just became a thing she did every day. For some people that can be helpful.”
You can download and read the study in full through the Journal of Obesity website. If you want to try weighing yourself daily and tracking your progress online, you can do so through a special Cornell University website set up by Levitsky. Registering is free, but you’ll need to listen first to a rather poorly produced five-minute audio explanation of the program by Levitsky.