This is the fourth in a six-part MyHealthNewsDaily series examining the problems and solutions related to six "winnable battles" in public health, as recently announced by the U.S. Centers for Disease Control and Prevention.

Americans are eager voyeurs into the lives of obese people on TV shows such as "The Biggest Loser" and "Huge," but they need not turn on the tube to find them. With one-third of the population greatly overweight, a simple walk down Main Street, USA offers ample evidence of a public health crisis that experts fear may only get worse.

Recently chosen as one of six "winnable battles" by the director of the CDC, obesity differs from other picks — namely, smoking, teen pregnancy and AIDS — in which Americans have made marked improvement over the last two decades.

Defined as weighing at least 100 pounds (45 kilograms) more than the ideal weight, or having a body mass index (BMI) of 35 or higher, the U.S. obesity rate among adults skyrocketed from 13.4 percent in 1962 to 35.1 percent in 2006, according to the National Institutes of Health (NIH). [Related: 11 Surprising Things That Can Make Us Gain Weight]

Is this battle winnable?

"The problem is, if you define winning as everyone taking off all the weight, and keeping it off forever, it's not winnable," said Judith Stern, a nutrition professor and obesity expert at the University of California, Davis. "It is a disease, a chronic disease, and I think this is really, really hard."

The obesity issue, however, is nothing if not controversial, generating passionate and polarized views. Dr. Henry Anhalt, a pediatric endocrinologist in Hackensack, N.J., called the CDC selection "a breath of fresh air," and disagreed with Stern’s opinion.

"I would be a defeatist if I didn't agree this battle is winnable," said Anhalt, whose patients include overweight children. About 17 percent of American children ages 6 to 19 are too heavy, according to the NIH.

Anhalt's optimism, he said, stems from the growing recognition of the main causes of obesity, including poor urban planning that leads to a lack of access to high-quality foods and easy access to nutrient-poor foods, and inadequate promotion of exercise in schools.

"These are things that are not impossible to fix," he said.

What it would take to win

Knowing the causes leads to logical solutions, Anhalt said, including adding more parks and walking or bike paths in developing communities, and enacting legislation that "compels the food industry to stop marketing high-calorie density, low-nutrition food to kids."

"We also need to get schools to buy into increasing the amount of physical exercise kids are getting to one hour a day," he said. The results of these steps would be dramatic, because people can lose weight quickly if such interventions are taken.

Stern told MyHealthNewsDaily obese people should try to lose weight in smaller  increments, rather than a lot at once. For example, she said, a 300-pound (136-kg) person who shed 10 percent of his body weight may remain dissatisfied because there's so much left to lose.

"You should set smaller goals," Stern said. "If you're breaking it down into steps, you're more likely to be able to maintain permanent weight loss."

Bariatric surgery, which prompts weight loss by limiting food intake or interfering with calorie absorption, can help obese people shed great amounts of weight over a relatively short time. More than 220,000 Americans underwent such a procedure last year, according to the American Society for Metabolic and Bariatric Surgery.

Anhalt and Stern pointed out the surgery's many health benefits, including quickly reversing diabetes in many patients, and lowering the risk of obesity-related conditions.

According to the NIH, obesity is associated with more than 150,000 deaths each year, most of them due to cardiovascular disease. Medical expenses associated with obesity were estimated at as much as $147 million in 2006, according to the CDC, and obese people incurred medical costs about $1,400 higher than those of normal weight.

While bariatric surgery isn't suitable for all, and comes with many risks, Stern said, it may be a decade before highly effective and safe weight loss drugs are developed by pharmaceutical companies and approved by the FDA.

Looking at the shorter term, Anhalt said his definition of victory in the obesity battle is modest, but doable.

"If you halt the progression, I consider that a win," he said.

This article was provided by MyHealthNewsDaily, a sister site to LiveScience.