Scientists at the Tel Aviv University have confirmed the long-held notion that sedentary lifestyle leads to obesity. Researchers said that the more time people spend sitting, the more fat they accumulate in the lower half of their bodies, or backside.
For the study, researchers analyzed the build up of fat in the body at the cellular level. They discovered that nutrition was not the only factor driving obesity and 'cellular expansion' also played an equally important role in fat production.
According to the latest survey conducted by the Centers for Disease Control and Prevention, more than 35 percent of American adults and 17 percent of American children are considered obese. Obesity causes diabetes, heart disease, stroke, and certain types of cancer, placing a huge burden on health care systems and the economy. The medical condition is usually treated through a combination of diet, nutrition, exercise, and other techniques.
The researchers wanted to know whether a sedentary lifestyle really contributes to obesity, besides providing more time to indulge in hamburgers.
"We found that fat cells exposed to sustained, chronic pressure - such as what happens to the buttocks when you're sitting down - experienced accelerated growth of lipid droplets, which are molecules that carry fats. Contrary to muscle and bone tissue, which get mechanically weaker with disuse, fat depots in fat cells expanded when they experienced sustained loading by as much as 50 per cent," Professor Amit Gefen, from the Department of Biomedical Engineering, said in a press release.
The scientists found that once the cells accumulated lipid droplets, its structure and mechanism changed dramatically. The cells became stiffer as they expanded, deforming other surrounding cells. The fat cells' neighbors are therefore pushed to change their shape and composition.
"When they gain mass and change their composition, expanding cells deform neighboring cells, forcing them to differentiate and expand," said Gefen. "This proves that you're not just what you eat.
Gefen said that understanding the etiology of obesity can help medical professionals to develop different practical solutions for the condition. Learning how the cells work can help scientists control fat production.
Researchers are now in the process of creating a platform to develop new therapies and technologies to avoid or reverse fat gain.
The finding is published in the Biophysical Journal.
