The word obesity gets often thrown around, but what is it really? What is obesity? Obesity is, in explicit terms, a description for extreme over weight. Obesity is quite prevalent, affecting almost a third of American adults -- sixty million or so people -- and roughly a billion people across the world.

You didn't read that wrong: nearly one billion persons the world over are obese.

As the rate of affliction in the US suggests, obesity is mostly seen in Western civilization. In what may be considered an unusual twist, obesity is considered a nutritional disorder. Putting aside how it gets labeled, obesity rates are on the rise: obesity numbers nearly doubled from 1991 through 1998.

The specific measure of obesity is being above what is considered average body weight by upwards of twenty percent. With respect to body fat measurements, obesity begins in males at more than twenty-five percent body fat, and more than thirty percent body fat in females. BMI, body mass index, is a standard means of documenting obesity. Someone who surpasses a 30 BMI iis documented obese.

Due to its increasing commoness, obesity is starting to frequently show in the financial costs paid by society. In the UK, the annual costs of obesity are estimated to run one billion pounds: currently about half a billion dollars US. UK financial costs from obesity are substantial, no question, but they represent a small drop in the bucket compared to American obesity costs. The regular monetary cost for obesity in the States is a staggering two hundred billion US dollars. At those prices, it's not difficult to have a clear understanding for why obesity is increasingly labeled an "epidemic" in the United States.

Obesity's big costs aren't any secret: it's almost entirely medical. Obesity ranks number one as a contributor to chronic illness, and comes in second to cigarette smoking in actually causing deaths. Medical and health problems linked to obesity reads similar to a grocery list: connected to coronary disease, to stroke, to Type 2diabetes, to ligament and joint strain from the pressure of excess bodyweight. Obese people tend to record high triglyceride levels and low HDL cholesterol levels.

Obesity is also connected with various sorts of cancer: kidney, throat, breast, colon, rectum. There's even some evidence that obese people have higher rates of Alzheimer's disease. And if the previous wasn't enough, a link exists between obesity and depression. All of these medical problems, multiplied by millions and millions of obese citizens. The end result is an enormous medical charge.

Though there are medical problems that can cause obesity, this scenario is exceptionally rare. Obesity resulting from secondary medical conditions is believed to constitute just one percent of every case of obesity. The vast majority of obesity cases come from lifestyle habits.