The difference between being obese or lean may be due to how much a person is apt to stand, pace, wriggle and shift about over the course of a day, a team of scientists reported in an intensive study of the consequences of fidgeting.
The researchers, who published their findings Friday in the journal Science, also suggested the amount of these mundane daily movements may be genetically ingrained – and that this would explain why some people can get away with being slouches without gaining weight while others, ostensibly no more lazy, become plump.
While this means some people are more likely to become overweight in today’s sedentary society, it does not mean they are fated to, said the study’s principal investigator Dr. James Levine, a consultant endocrinologist and professor of medicine at the Mayo Clinic in Rochester, Minn.
The extra energy burned by the fidgety lean group was about 350 calories a day – well within the reach of most people. The extra calorie burn amounts to at least 10 pounds a year.
In the study, 20 volunteers – 10 lean and 10 mildly obese – were monitored for 10 days in their own homes as they went about their normal daily routines. All of the participants considered themselves to be “couch potatoes.”
The study involved 150 scientists and other personnel to prepare calorie-controlled meals, monitor subjects, analyze data and conduct other tasks.
Each participant wore a special, high-tech set of underwear, which were rigged with sensors and data loggers originally designed to monitor jet fighter motion. The underwear could track most body movements.
Fresh undergarments were supplied each day. Data from the used underwear were downloaded each day to a computer.
“This enabled us to gain a window into lean and obese people’s lives that had hitherto been invisible,” Levine said.
The scientists found that even though all members of the study considered themselves to be couch potatoes, the obese individuals actually spent 164 more minutes sitting each day than the lean people.
There was the possibility that the obese group fidgeted less simply because they were overweight.
To test the idea, the scientists instructed the obese group to lose weight. But even after doing so, they still moved around less. This suggested that they were innately more sedentary than the lean group – a tendency that could likely be the cause of their obesity.
The scientists over-fed the lean group to see if they would slow down more as they fattened up. They remained just as fidgety as before.
“I think it’s really interesting – and it fits in well with the idea that the difference between obesity and lean-ness is very small, just a little bit of activity here and there,” commented James Hill, director of the University of Colorado’s Center for Human Nutrition in Denver.
Hill said that burning 350 calories is equivalent to taking about 7,000 extra steps a day.
“It’s really not that hard,” he said. “If you have this natural tendency to fidget that’s an advantage to you, but if you don’t, don’t despair. You can intentionally get some of that physical activity back into your day by walking.”
Levine recommended that people who are not constantly on the move as a matter of habit make a few tiny changes to accomplish the same end.
“It wouldn’t do any harm to do a little vacuuming before work,” he said. “Park in parking lot B and have an extra walk to the office.”
Levine said that instead of a desk and chair, his own office is outfitted with a treadmill mounted with a computer. The treadmill is set at a leisurely 0.7 mph, and he now types as he strolls.
“I used to sit … 10 hours a day,” he said. “Now I’m walking 10 hours a day.”