Couch potato time is an activity that grows fat cells
If you think time spent on the couch is just time spent chilling out, think again. Researchers say sitting in front of the TV or computer is actually time spent getting fatter that contributes to obesity even for people who count calories and exercise. Time spent on the couch produces 50 percent more fat cells, compared to when we're up and moving.
Prof. Amit Gefen of Tel Aviv University’s Department of Biomedical Engineering, says,
"Obesity is more than just an imbalance of calories. Cells themselves are also responsive to their mechanical environment. Fat cells produce more triglycerides, and at a faster rate, when exposed to static stretching”, which means lying around doing nothing.
In the lab Gefen and his colleagues stimulated preadipocytes (precursors to fat cells) with glucose or insulin to coax them into fat cells.
Gefen studies patients who are wheelchair bound or bedridden and develop chronic wounds.
With the help of MRI’s, Gefen discovered muscles of patients who are inactive become invaded with lines of fat cells.
The discovery led Gefen to investigate how mechanical load from sitting or lying in bed promotes the invasion of fat cells into major muscle groups.
The researchers cultured immature fat cells (preadipocytes), placing them in a cell-stretching device. They also attached the cells to an elastic molecule to mimic what happens to from sitting and lying around too much.
The researchers compared the stretched cells to another group that were not stretched.
After just two weeks the test showed both groups of cells developed fatty droplets. But the ones that were subjected to prolonged stretching had 50 percent more fat than the control cultures.
There are various ways that cells can sense mechanical loading," Gefen explains, which helps them to measure their environment and triggers various chemical processes.
It appears that long periods of static mechanical loading and stretching, due to the weight of the body when sitting or lying, has an impact on increasing lipid production." Lipids are fatty molecules.
The message says Gefen is that prolonged periods of inactivity can thwart an otherwise healthy lifestyle that contributes to obesity.
He says we need to take into account how much time we spend being inactive, behind a desk of lying on the couch, in addition to how much we eat and how many calories we burn.
Even for people who exercise frequently, couch potato time is time spent growing fat cells that can promote obesity. The study, published in the American Journal of Physiology — Cell Physiology, helps explain recent studies that time spent in front of the TV, at our computers at work and just sitting for too long can lead to a variety of health problems, shorten life span and even raise the risk of cancer.
Am J Physiol Cell Physio: doi:10.1152/ajpcell.00167.2011
"Static Mechanical Stretching Accelerates Lipid Production in 3T3-L1
Adipocytes by Activating the MEK Signaling Pathway"
Naama Shoham et al.