NBC’s hit show, "The Biggest Loser", starts each season with a cast of severely overweight people; lately several have been morbidly obese. We’re introduced to these people and learn why they want to change their lives. A few of the younger contestants are desperately looking for love. Romantic love typically leads to sex. And well, it seems obesity and sex don’t always go together.

It’s no exaggeration that obesity is epidemic. Globally, there are more than one billion overweight adults. Nearly 300 million of them are obese. In the United States, the Center for Disease Control reports more than 400,000 adults are obese.

Obesity is associated with numerous health problems like type 2 diabetes, cardiovascular disease, hypertension and stroke, and certain forms of cancer. The public is aware of these health issues, but the risk of sexual problems isn’t quite as well known.

One sexual problem is erectile dysfunction. It is linked to medical problems such as diabetes, hypertension and elevated cholesterol.

The physical limitations of excess weight can make sexual activity too strenuous. The constant feelings of lethargy, caused by obesity, also tend to diminish a person's sex drive. In many cases, the heavier a person gets, the less they’re interested in sex and the less sex they get, the more they crave satisfaction from food.

According to one study, the obese reported 25 times as many problems in their sex lives, compared to people with healthy weight levels. Both men and women experienced a lack of sexual desire and enjoyment coupled with hampered performance.

Martin Binks, a Director of Behavioral Science at Duke University's Diet and Fitness Center, and his colleagues surveyed nearly 1,000 obese people. They found those suffering from obesity sometimes, usually or always felt no desire for sex, compared to just two percent of those who were not obese.

About four out of every 10 reported physical problems with sex; 41 percent said they avoided sex. In contrast, just 2.5 percent of the non-obese people said they stayed away from sexual activity.

There is also a social stigma attached to obesity. People who suffer from it often find themselves stared at in the street or the victim of verbal and psychological abuse. This can lead to self-esteem issues which in turn adversely affect one’s sex life.

Obesity is by no means a roadblock to sexual activity. The two can coexist, but it certainly puts up some obstacles.

Stacy Lloyd is a writer and video producer in Phoenix, Arizona. A former television news journalist, she covered stories around the world. Currently, she produces corporate and non-profit videos and broadcast programming.