Obesity: Not Just What You Eat


March 20, 2014
Health

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 cellular level. According to their findings, nutrition is not the only factor driving obesity. The mechanics of “cellular expansion” plays a primary role in fat production, 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 fat content 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 obesity,” Prof. Gefen says. “If you can learn to control the mechanical environment of cells, you can then determine how to modulate the fat cells 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 fat production.




Obesity: Not Just What You Eat

3 Responses to Obesity: Not Just What You Eat

  1. Betty Ntuli (13411404) April 30, 2014 at 5:55 am #

    Obesity can be dangerous as it can contribute to the death of a person by the chronic illness lead to. I always thought that it was bought about unhealthy diet and lifestyle but now i know that is not the case as there are many factors that are contributing to it. I believe that the more informative we become the better chances of finding ways to beat this because we cannot rely on excise and “healthy eating.

  2. Angella(u14230705) April 30, 2014 at 5:23 am #

    u14230705

    Obesity can lead to many chronic diseases which can eventually kill someone. Obesity is manageable if one eats healthy and exercises, by doing all this one can reduce chances of getting other diseases. I understand that obesity is caused by unhealthy eating habits and being unfit but it can also be inherited from parents and it should be ones priority to find out their family history so that their able to take steps to minimize chances of being obese.

  3. Carmen March 21, 2014 at 5:59 am #

    The blog posting gave me new insight to what really causes obesity. I was under the impression that obesity is mostly caused by unhealthy food and nutritional decisions. In the last few months of my studies at university I discovered that obesity can also be inherited by our ancestors and that if you have this “obesity” gene your eating habits will not be the main influence of your weight problems. We cannot at this point alter our genes, but knowing this can give us a better understanding towards overweight individuals. The knowledge that you give in this blog posting gives another cause of obesity known as “cellular expansion”. This emphasize the fact that a good percentage of times obesity cannot be prevented by exercise and healthy eating. Being obese is a big struggle to overcome and now we know why- our genes are usually the culprits!

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