Obesity, the most serious public health problem in America, has yet to be honestly discussed.

After studies in the 1960s clarified the health impacts of cigarettes, by contrast, smoking became an object of concerted public-health efforts. Smokers were increasingly ostracized, greatly reducing the incidence of smoking in the United States. Yet holding obese people responsible is still considered not only politically incorrect, but discriminatory and prejudiced.

Indeed, U.S. trends in smoking and obesity have headed in opposite directions. Over the past 15 years, smoking rates have declined by 20 percent, while obesity rates have increased by 48 percent. Since virtually everyone in America knows that both smoking and obesity worsen one's health — and since millions of Americans have chosen to quit smoking or take steps to lose weight — it's reasonable to conclude that others have decided to continue these behaviors and accept the adverse long-term effects.

We need to usher in a new era of personal responsibility in health care, and obesity should be our highest priority.

The first important step is to admit that although some people may be more predisposed than others to harmful behaviors and adverse outcomes, increasing rates of obesity are primarily due to overeating and insufficient exercise. Although the causes of obesity are complex, only a limited number of cases are primarily due to genetics. The genetics of populations change far too slowly to account for the sharp increase in obesity rates of recent years, and genetics cannot explain the increasing prevalence of obesity in the United States first and most severely, and subsequently in developing countries.

Heavy burden

The burden of obesity on the U.S. health-care system and taxpayers is at crisis levels, and it's only expected to increase in coming decades. Extra medical care due to obesity makes up 5 to 10 percent of total U.S. health-care costs, half of which is financed by Medicare and Medicaid.

Due to the prevalence of obesity and its association with multiple chronic diseases, poorer treatment outcomes, complications from even the best medical and surgical care, increased levels of disability, work absenteeism, and premature death, its total societal cost exceeds $215 billion a year in the United States. Pennsylvania, New York, Texas, and California each spend more than $4 billion annually treating health problems that result from obesity. "Keeping obesity rates level could yield a savings of nearly $550 billion in medical expenditures over the next two decades," Eric Finkelstein of Duke University predicted recently.

There is no silver bullet to solve the relentless progression of obesity. But government policy can play a crucial role. Giving consumers access to information and education is essential, and the power of fully transparent calorie and nutritional content cannot be overstated.

Food censorship

However, arbitrary "food censorship" limiting choices or portion sizes in restaurants and grocery stores — as has been instituted or contemplated by cities around the country — is only another ill-advised, paternalistic overreach of government, one based on the simplistic assumptions of people who lack basic trust in and respect for individual Americans.

Aggressive support of research and development by America's medical scientists and entrepreneurs is critical, though. For instance, the National Institutes of Health's strategic plan to encourage obesity research, including more effective prevention and treatment strategies, should be a priority.

Facilitating clinical trials and streamlining approval of innovative treatments are also important. After several years in which no new obesity drugs were approved, a Food and Drug Administration advisory committee recommended three approvals in the past four months. This is a good sign, but the recent trends toward longer bureaucratic delays in drug and device approvals must be reversed.

Meanwhile, well-intentioned insurance regulations must not eliminate personal responsibility in the guise of fairness. President Obama's health-care law includes coverage guarantees and price controls that unintentionally relieve people of personal accountability, shifting costs from those opting to follow risky lifestyles to those who take more responsibility for their own health. Similar measures at the state level have led to excessive premiums and pushed healthy people — the very people for whom the health law's insurance mandate is intended — out of the market.

Health insurance should instead follow the precedents of life and automobile insurance: Prices should hold individuals accountable for voluntary and reckless behavior. Life insurance premiums are markedly higher for those who engage in dangerous behaviors such as smoking. Risky driving is a key factor in determining automobile insurance rates. Because obesity is a high-risk lifestyle with well-known hazards, health insurance rates that reflect higher risks of disease and more frequent use of medical care are totally appropriate.

It is illogical, counterproductive, and even unfair for society, rather than the individuals responsible, to pay for destructive decisions such as cigarette smoking and overeating, two major drivers of health spending in the United States. And more and more Americans think so. In 2010, 54 percent of Americans thought smokers should pay more for health insurance; now 72 percent do.

Private-sector employers and others with a stake in health care must play a greater role. Research has demonstrated the clinical efficacy of measures to encourage both smoking cessation and weight loss, including financial incentives. A growing number of employers are charging smokers higher insurance premiums while also offering free wellness programs that include risk assessments and free screenings for risk factors such as high blood pressure, body mass index, and cholesterol. These programs often offer financial benefits to workers, including lower insurance premiums and employer contributions to health savings accounts. Such incentives should be promoted.

More to come

Obesity is a uniquely urgent crisis in the United States. Americans are the fattest people in the world. The prevalence of obesity is significantly greater in America than in all the world's other wealthy nations. Americans are about twice as likely as Western Europeans or Canadians to be obese, three to four times more likely than Scandinavians, and 10 times more likely than the Japanese, who enjoy the world's greatest longevity.

It's even more sobering that there is an estimated lag of 25 years before obesity's total effect on premature death and disease manifests itself. Given the higher rates and predicted trends of obesity among American children and adults, health gains over the past century could be wiped out by obesity's deleterious effects on disease outcomes and life expectancy, which will be seen for decades to come if the current situation is not remedied.

No easy solution is apparent. But the most effective message government and society can send is to hold individuals accountable for their decisions.

Scott W. Atlas, M.D., is a senior fellow at Stanford University's Hoover Institution and the author of "In Excellent Health: Setting the Record Straight on America's Health Care" (Hoover Press, 2011).