Weight control is not quite that simple, as it turns out.
According to the Centers for Disease Control and Prevention (CDC), maintaining body weight is a struggle for many adults in the United States, about 39.8% of whom have obesity.
Although the popular advice is that taking 10,000 steps a day is the way to keep off extra pounds, a new study from Brigham Young University (BYU) in Provo, UT, finds that this is essentially a myth.
Taking 10,000 steps a day may have other fitness benefits, but it will not by itself prevent a person from gaining weight, according to the BYU study, which appears in the Journal of Obesity.
There are clear health benefits to maintaining a moderate weight, even though there is no single straightforward calculation to determine a person’s optimal weight.
The closest thing to a standard metric is body mass index (BMI), but this measurement also has its limitations.
The notion that 10,000 steps are somehow a magic number for weight stability has a surprisingly unscientific origin.
Its initial proposal was in 1965 advertisements for a pedometer that was on sale in Japan. Inventor Yoshiro Hatano called it the “manpo-kei.” “Manpo” means “many steps.”
The 10,000 steps figure seemed to Hatano to be a healthy and marketable amount of walking.
Some contemporary modern pedometer-based fitness trackers also reference the figure.
The company behind one of these — Fitbit — note, however, that 10,000 steps do add up to about 5 miles or 30 minutes of exercise each day, which roughly meets the CDC’s recommendation of exercising for 150 minutes a week.
Researchers from the Exercise Science Department and the Nutrition, Dietetics & Food Science Department at BYU decided to investigate this figure further.
The goal of the study was to test the hypothesis that taking 10,000 or more steps each day would keep weight and fat gain under control in first year college students.
To that end, 120 female students in their first 6 months at BYU counted their steps on 6 days of the week for 24 weeks. The researchers divided the students into three groups, each taking a certain number of steps a day.
The first group walked about 10,000 steps a day. The second group increased that by 25% to 12,500 steps, and the third went up again to 15,000 steps.
Researchers recorded the participants’ weight at the beginning of the study period and again at the end, tracking their calorie intake throughout the trial.
In addition, they measured each participant’s body composition — that is, fat-free mass, fat mass, lean mass, percent body fat, visceral adipose tissue, and visceral fat — using dual X-ray absorptiometry.
The researchers found that all of the students put on weight over the duration of the study, regardless of the number of steps they took.
The average weight gain was approximately 1.5 kilograms (kg), which is within the 1–4 kg weight gain range that students typically experience during their first academic year.
In terms of body composition, surprisingly, most of the weight that the participants gained was lean tissue (56%) as opposed to adipose tissue (44%). As well as not affecting weight gain, the number of steps had no significant effect on body composition after the trial.
The authors note three limitations of the study:
- There was no control group with which to compare the participants’ results.
- It did not test step counts below 10,000, but, the authors note, “it is possible that lower step recommendations may have allowed us to see more effects on weight.”
- There was a significant dropout rate, particularly among the 15,000-step group, potentially unbalancing the results.
The researchers point out that walking may deliver other health benefits, and even emotional ones.
“If you track steps, it might have a benefit in increasing physical activity, but our study showed it won’t translate into maintaining weight or preventing weight gain.”
– Bruce Bailey, lead author
“Exercise alone,” Bailey concludes, “is not always the most effective way to lose weight.”
The CDC advise that an effective weight maintenance program must include a healthful diet in addition to daily exercise.