When it comes to dealing with the growing medical and social crisis of obesity in America, public health policy expert Jay Bhattacharya of Stanford University said there is only one law that truly comes into play: The law of unintended consequences.

Bhattacharya, who since the mid-2000s has been studying both the costs of obesity and the impact of possible solutions, offers the example of a proposed tax on ground beef, which would take aim at the problem of children from low-income families getting too many of their daily calories from high-fat, fast-food hamburgers.

In many low-income neighborhoods, however, those hamburgers from McDonald’s or Burger King may also be the only sources of iron children have, Bhattacharya noted during a recent health policy lecture for the University of Pennsylvania’s Leonard Davis Institute of Health Economics. A high tax on beef might price fast-food burgers out of reach for low-income families, which in turn could increase cases of anemia among poor children, creating a new public health problem.

“Obesity is not the only outcome of food,” Bhattacharya said during his speech, titled, “Who Pays for Obesity?” Unlike cigarette smoking, which has clear public health consequences but offers no social benefits, people need to eat daily to live, making it all the more difficult to regulate overeating.

In fact, according to Bhattacharya, an effective tax to discourage obesity would begin at an individual’s 2,500^th calorie of the day — an idea that would be not only impractical, but impossible to carry out.

The taxing difficulties that Bhattacharya raised during his lecture are just some of the complications that America faces in tackling the rising costs, both economic and social, of obesity.

Indeed, Bhattacharya laid out a variety of factors affecting obesity policy in America, including Social Security and Medicare policies; agricultural price supports, and governmental and philanthropic funding for biomedical research. In addition, social factors well beyond the reach and influence of regulators also lead to unintended consequences and sometimes contradictory outcomes.

Some proposed solutions, he stated, do not even tackle the real problems. For example, well-intended policy advocates have called for taxes on sugar and other sweeteners because obese children get many of their calories through sugary drinks. “I don’t believe the solution to [ending] obesity among poor people is to raise the price of sugar,” Bhattacharya stated. “When you look at the total price of a sweetened drink, most of it is actually marketing — most of the price of a can of Coke is the marketing.” What’s more, he added, drinks such as orange juice that also have a positive health impact would be affected by such a tax.

Few experts would disagree that obesity is a major health issue in the United States. Although obesity has been rising throughout the world in recent decades because of easier access to high-calorie junk foods, lack of exercise and other factors, the number of Americans who are overweight or obese is particularly alarming. The percentage of obese U.S. adults grew in one short decade — from 1997 to 2007 — from 19.4% to 26.6%, with childhood obesity also emerging as a major new health problem.

The cost of obesity to the American economy is enormous as well, largely due to increased medical costs, including hospitalization, for weight-related maladies such as heart disease, diabetes, hypertension and stroke; one major federal study in 2003 pegged that price tag at $75 billion annually, a figure that has surely risen sharply since then. Alarm over these trends has prompted government on both the local and national levels to attempt to tackle the problem, from broad public awareness campaigns by the likes of First Lady Michelle Obama to cities that have sought to ban outright the high-calorie trans-fats in restaurant food.

For Bhattacharya, the question regarding obesity is whether the problem is a public health issue; that is, are the substantial costs of obesity imposed on all citizens — regardless of their personal eating and exercise habits — or is only the overweight individual paying most of the financial burden himself?

“Obesity costs a lot,” Bhattacharya noted. “To me, this is not the question. The question is not does it cost a lot to take care of a person who is obese. The key question is: Who pays?” If research shows that the out-of-pocket costs of obesity are largely paid by individuals, he said, this undercuts the argument that obesity is a public health crisis that then requires extensive government intervention.

Bhattacharya and his colleagues focused on health insurance as the arena where Americans are potentially most impacted by the cost of obesity. He said he was particularly interested in typical employer-provided health care, in which the costs of coverage are pooled among all employees, since that could lead to a transfer of dollars from thin employees — who have lower medical costs on average — to overweight ones.

But Bhattacharya’s research has shown that employees of companies that provide health insurance to all workers earn less money on average if they are obese. In other words, businesses compensate for the higher health-insurance costs related to its overweight workers by paying those workers lower wages. That means that when all is said and done, obese Americans are actually paying the price for their health issues.

Bhattacharya — who looked at federal wage and health data for workers in the age 20-50 category — found that for employees who do not have company-provided health insurance, there was virtually no wage differential between obese workers and their non-obese colleagues. The research also showed that while more generous insurance increased the willingness of people to visit a doctor, the better insured did not become more obese.

“The underlying principle behind all of this work is — should we tax people for their bad body decisions?” Bhattacharya asked. “I’m still not convinced that the answer is ‘no,’ but I still don’t know yet that the answer is ‘yes.’”