Obesity: Not just what you eat—Research shows fat mass in cells expands with disuse

March 20, 2014
Obesity: Not just what you eat--Research shows fat mass in cells expands with disuse

Over 35 percent of American adults and 17 percent of American children are considered obese, according to the latest survey conducted by the Centers for Disease Control and Prevention. Associated with diabetes, heart disease, stroke, and even certain types of cancer, obesity places a major burden on the health care system and economy. It's usually treated through a combination of diet, nutrition, exercise, and other techniques.

To understand how obesity develops, Prof. Amit Gefen, Dr. Natan Shaked and Ms. Naama Shoham of Tel Aviv University's Department of Biomedical Engineering, together with Prof. Dafna Benayahu of TAU's Department of Cell and Developmental Biology, used state-of-the-art technology to analyze the accumulation of fat in the body at the . According to their findings, nutrition is not the only factor driving obesity. The mechanics of "cellular expansion" plays a primary role in , they discovered.

By exposing the mechanics of fat production at a cellular level, the researchers offer insight into the development of obesity. And with a better understanding of the process, the team is now creating a platform to develop new therapies and technologies to prevent or even reverse fat gain. The research was published this week in the Biophysical Journal.

Getting to the bottom of obesity

"Two years ago, Dafna and I were awarded a grant from the Israel Science Foundation to investigate how mechanical forces increase the within fat cells. We wanted to find out why a sedentary lifestyle results in obesity, other than making time to eat more hamburgers," said Prof. Gefen. "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%. This was a substantial discovery."

The researchers discovered that, once it accumulated lipid droplets, the structure of a cell and its mechanics changed dramatically. Using a cutting-edge atomic force microscope and other microscopy technologies, they were able to observe the material composition of the transforming fat cell, which became stiffer as it expanded. This stiffness alters the environment of surrounding cells by physically deforming them, pushing them to change their own shape and composition.

"When they gain mass and change their composition, expanding cells deform neighboring cells, forcing them to differentiate and expand," said Prof. Gefen. "This proves that you're not just what you eat. You're also what you feel—and what you're feeling is the pressure of increased weight and the sustained loading in the tissues of the buttocks of the couch potato."

The more you know …

"If we understand the etiology of getting fatter, of how cells in fat tissues synthesize nutritional components under a given mechanical loading environment, then we can think about different practical solutions to ," Prof. Gefen says. "If you can learn to control the mechanical environment of cells, you can then determine how to modulate the to produce less fat."

The team hopes that its observations can serve as a point of departure for further research into the changing cellular environment and different stimulations that lead to increased production.

Explore further: 'Just chill?' Relaxing can make you fatter

Related Stories

'Just chill?' Relaxing can make you fatter

December 1, 2011
Conventional wisdom says that exercise is a key to weight loss — a no-brainer. But now, Tel Aviv University researchers are revealing that life as a couch potato, stretched out in front of the TV, can actually be "active ...

Researchers distinguish subcutaneous from visceral fat stem cells using specific cell markers

February 20, 2014
Scientists from A*STAR's Singapore Bioimaging Consortium (SBIC) led in the discovery that two little-known fat cell markers have huge potential to assist researchers to further their understanding of fats. The discovery was ...

Reducing liver protein SIRT1 levels

January 22, 2014
A new study led by Boston University School of Medicine (BUSM) demonstrates that the abnormal metabolism linked to obesity could be regulated in part by the interaction of two metabolic regulators, called the NAD-dependent ...

Newly discovered brown fat cells hold possibilities for treating diabetes, obesity

November 21, 2013
Obesity and diabetes have become a global epidemic leading to severe cardiovascular disease. Researchers at the University of Utah believe their recent identification of brown fat stem cells in adult humans may lead to new ...

Study reveals origins of body fat

February 24, 2013
(Medical Xpress)—Yale School of Medicine researchers have answered a question millions regularly and plaintively ask themselves: Where did all that fat come from?

Recommended for you

Study finds 90 percent of American men overfat

July 24, 2017
Does your waist measure more than half your height?

Are sugary drink interventions changing people's behaviour?

July 19, 2017
An evaluation of efforts designed to reduce how many sugary drinks we consume shows some success in changing younger people's habits but warns they cannot be the only way to cut consumption.

Young adult obesity: A neglected, yet essential focus to reverse the obesity epidemic

July 18, 2017
The overall burden of the U.S. obesity epidemic continues to require new thinking. Prevention of obesity in young adults, while largely ignored as a target for prevention and study, will be critical to reversing the epidemic, ...

Weight gain from early to middle adulthood may increase risk of major chronic diseases

July 18, 2017
Cumulative weight gain over the course of early and middle adulthood may increase health risks later in life, according to a new study led by researchers from Harvard T.H. Chan School of Public Health. They found that, compared ...

Study finds children carry implicit bias towards peers who are overweight

June 23, 2017
Even children as young as 9 years old can carry a prejudice against their peers who are overweight, according to a new study led by Duke Health researchers. They might not even realize they feel this way.

Mother's obesity boosts risk for major birth defects: study

June 15, 2017
Children of obese women are more likely to be afflicted by major birth defects, including malformations of the heart and genitals, according to a study published on Thursday.

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.