Non-exercise activity is far more important for leanness than hitting the gym, suggests a complex study that involved high-tech underwear monitoring participants 24 hours a day.
The study shows that everything from tapping toes to cleaning the basement boosts what’s been dubbed non-exercise activity thermogenesis&emdash;”NEAT”&emdash;and plays a large role in determining who is lean and who is obese.
“A person can expend calories either by going to the gym, or through everyday activities,” says study leader James Levine of the Mayo Clinic in Rochester, Minnesota. “Our study shows that the calories that people burn in their everyday activities&emdash;their NEAT&emdash;are far, far more important in obesity than we previously imagined.”
In the study, obese people sat on average 150 minutes more each than lean people, burning 350 fewer calories per day. And importantly for understanding the origins of obesity, the difference appeared to be biological.
“It most likely reflects a brain chemical difference because our study shows that even when obese people lose weight they remain seated the same number of minutes per day,” says Levine. “They don’t stand or walk more. And conversely, when lean people artificially gain weight, they don’t sit more. So the NEAT appears to be fixed.”
Is that a sensor in your pants?
The findings are based on a complex study involving more than 150 people who helped in planning, design, invention, food preparation and data analysis.
Ten obese and 10 lean participants were fitted with a special monitoring system invented by Mayo Clinic researchers.
Incorporating technology used in fighter-jet control panels, the system uses sensors in data-logging undergarments&emdash;bottoms like bicycle shorts, women’s tops like sports bras and men’s like undershirts.
Participants wore the undergarments 24 hours a day, getting a fresh pair each morning at breakfast when they were also weighed and their clothing’s data downloaded.
Using the system, researchers monitored the body postures and movements of participants for 10 days. The only things participants were forbidden to do were swim and eat food the research team didn’t prepare for them.
Next, they overfed lean participants by 1,000 calories per day and underfed obese participants by 1,000 calories per day.
They then monitored participants’ movements every half second for 10 days.
Encouraging “NEAT-seeking”
Comparing results, the researchers found that even after losing weight, the naturally obese group sat more and moved less. And even after gaining weight, the naturally lean group moved around more.
The researchers conclude that obese people are NEAT-deficient, possibly because of a cognitive defect in processing biological drives and environmental cues.
They think that the findings could be used to help reverse obesity trends, such as by encouraging “NEAT-seeking” behavior.
“This is entirely doable, because the kind of activity we are talking about does not require special or large spaces, unusual training regimens or gear,” says Levine. “Unlike running a marathon, NEAT is within the reach of everyone.”
