Spandex may make you think of disco or workout gear. But because this wonder fiber can stretch more than a 100 percent and snap right back to shape, its claim to fame may just be that it has clothed Americans as obesity rates have soared.

In a country with a rampant obesity epidemic, many patients say their doctors don't spend enough time talking with them about losing weight. But doctors often complain that when they do bring up the issue, nothing changes.

Most people who lose weight end up gaining it back — and it's not just a matter of willpower. In fact, once we begin to shed those first few pounds, says one expert, "the biology really kicks in and tries to resist the weight loss."

Companies are trying to bring down their spiraling health care costs by helping employees lose weight. At Dow Chemical, managers hope to set an example by hitting the corporate gym at midday, and the company offers weight-management classes on demand, at workers' convenience.

From cubicle farms to auto factories, accommodating larger and heavier employees has become a fact of life. One in three U.S. adults is obese, and researchers say the impact on business can be boiled down to a number: $1,000 to $6,000 in added cost per year for each obese employee.

Though Colorado is often held up as the model of a healthy lifestyle, the state isn't immune to the obesity crisis. One in four children is either overweight or obese. "This is a major problem," says one state health official. "We are far from setting the model of where we want to be."

One of the fastest growing segments of the weight-loss market is surgery. But doctors warn that it should not be seen as a quick fix. Indeed, though surgery can help with diabetes and high blood pressure, some patients struggle with health issues even years after going under the knife.

While many obese people lead happy and healthy sex lives, counselors and therapists are seeing more obese clients with problems in the bedroom. A pattern is clear: Obese people are more dissatisfied with their sexual lives, and women seem to suffer the most.

Holmes County is the most obese county in Mississippi, the most obese state. The county is also among Mississippi's poorest. Officials are trying to get families to make healthier choices, and a co-op that farms the fertile Delta land is trying to steer residents toward fresh food.

From The Honeymooners to The Biggest Loser, television has rarely dealt sensitively with issues of weight. As part of an ongoing series on obesity in America, Alex Cohen explores the limited number of roles for overweight actors — from "bumbling husband" to "sassy best friend."