"Death by chocolate" could soon be more than an extravagant dessert — obesity may soon become the No. 1 preventable killer of Americans, the surgeon general said Thursday.

If obesity continues to grow as an epidemic, it could surpass cigarette smoking as the leading cause of death in the U.S.

Calling a war against dangerously big waistlines, Surgeon General David Satcher demanded changes in policies from schools to the fast-food industry to slim down the United States before the arrow on the scale points to "Death."

Some 300,000 people a year die from illnesses directly caused or worsened by being overweight. In addition, obesity could wipe out progress scientists have made fighting cancer and heart disease, Satcher warned.

Obesity is something every American has to deal with, either personally or through friends and family. Some 60 percent of adults are overweight or obese, as are nearly 13 percent of children, rates that have steadily risen over the past decade.

The reason isn't a mystery: People eat more calories — too often by shunning fruits and vegetables in favor of super-sized junk foods — than they work off. But how to solve the problem is vexing, as warning after warning from health officials has gone unheeded.

Among the facts detailed in the report:

• Even being 10 to 20 pounds overweight increases the risk of premature death. The risk rises rapidly when people become obese.

Obesity is defined as a score of 30 or more on the body-mass index, the comparison of height to weight. A healthy weight is a BMI of less than 25. BMI is derived by multiplying a person's weight in pounds by 703 and dividing that result by height in inches squared.

• Increase your poundage and you'll also increase the risk of heart disease, diabetes, cancer, asthma and other illnesses. Women who gain more than 20 pounds after age 18 double their risk of postmenopausal breast cancer. Every 2-pound increase in weight increases the risk of arthritis by at least 9 percent.

• Losing weight means both eating less and exercising more. Forgoing one 12-ounce soft drink or adding 30 minutes of brisk walking most days can, over a year, help you lose about 10 pounds.

But people can't fight obesity alone. Satcher called for a national attack on obesity like the one federal health officials declared on smoking.

Among his recommendations:

• Schools must provide daily physical education for every grade. Physical education has gradually been disappearing, particularly for older students. Just 6 percent of schools require P.E. for high-school seniors.

• Schools must provide healthier food and better enforce federal rules restricting junk food in schools. Agriculture Department rules say school lunches should contain no more than 30 percent fat, but the national average is 34 percent. A recent survey found just 20 percent of high-school lunches provide proper vitamin levels.

• Communities must create safe playgrounds, sidewalks or walking trails, particularly in inner cities. Employers should provide time for workers to get physical activity on the job. And the companies benefit, he said, because healthier workers mean employers' insurance and absenteeism costs will drop.

• Industry should promote healthier food choices, including "reasonable portion sizes."

The poor have a tendency to be fattest. Among the reasons, Satcher said, was that fast food is crowding out healthier foods in inner cities.

"Sometimes the most fattening foods are the cheapest," Satcher lamented in an interview.

He urged communities to study fast-food marketing practices, comparing the situation to tobacco companies' targeting of inner-city minority communities in the 1990s. And he encouraged government-funded attempts to get people to eat more fruits and vegetables.

But the National Restaurant Association rejected as "simplistic" the idea that fast-food joints cause obesity, and the National Soft Drink Association urged more focus on Satcher's exercise recommendations, calling vending machines in schools adequately regulated.

Consumer advocates, on the other hand, praised the report for finally acknowledging that people's environments can either help or hinder weight loss. But "talk is cheap," said Margo Wootan of the Center for Science in the Public Interest. She asked how the government would implement Satcher's recommendations.

The Agriculture Department has targeted childhood obesity but hasn't decided what to do exactly, said Ron Vogel of the special nutrition program. Officials are helping schools to improve lunch nutrition, but the USDA has authority to restrict vending machines only in cafeterias. The USDA is considering whether to seek broader authority.

As for physical education, the Education Department can't force schools to require it because the decision is made locally, spokesman Dan Langan said. But this fall, it did provide $5 million in grants to help 18 school districts begin or expand P.E. classes.

As for overweight Americans, don't get discouraged if a diet doesn't cause as much weight loss as expected, Satcher said. Even losing 10 pounds can reduce someone's risk of getting diabetes or heart disease, as can simply walking 30 minutes a day.

"Every pound counts," he said.

The Associated Press contributed to this report.