Smoking has the most obvious impact. Studies have increasingly shown harm to nonsmokers who are unlucky enough to work or live around heavy smokers. And several studies have shown heart attacks and asthma attack rates fell in counties or cities that adopted big smoking bans.
"When you ban smoking in public places, you're protecting everyone's health, including and especially the nonsmoker," said S. Jay Olshansky, a professor at the University of Illinois-Chicago's School of Public Health.
It can be harder to make the same argument about soda-size restrictions or other legislative attempts to discourage excessive calorie consumption, Olshansky added.
"When you eat yourself to death, you're pretty much just harming yourself," he said.
But that viewpoint doesn't factor in the burden to everyone else of paying for the diabetes care, heart surgeries and other medical expenses incurred by obese people, noted John Cawley, a health economist at Cornell University.
"If I'm obese, the health care costs are not totally borne by me. They're borne by other people in my health insurance plan and — when I'm older — by Medicare," Cawley said.
From an economist's perspective, there would be less reason to grouse about unhealthy behaviors by smokers, obese people, motorcycle riders who eschew helmets and other health sinners if they agreed to pay the financial price for their choices.
That's the rationale for a provision in the Affordable Care Act — "Obamacare" to its detractors — that starting next year allows health insurers to charge smokers buying individual policies up to 50 percent higher premiums. A 60-year-old could wind up paying nearly $5,100 on top of premiums.
The new law doesn't allow insurers to charge more for people who are overweight, however.
It's tricky to play the insurance game with overweight people, because science is still sorting things out. While obesity is clearly linked with serious health problems and early death, the evidence is not as clear about people who are just overweight.
That said, public health officials shouldn't shy away from tough anti-obesity efforts, said Callahan, the bioethicist. Callahan caused a public stir this week with a paper that called for a more aggressive public health campaign that tries to shame and stigmatize overeaters the way past public health campaigns have shamed and stigmatized smokers.
National obesity rates are essentially static, and public health campaigns that gently try to educate people about the benefits of exercise and healthy eating just aren't working, Callahan argued. We need to get obese people to change their behavior. If they are angry or hurt by it, so be it, he said.
"Emotions are what really count in this world," he said.