When the Federal Trade Commission tried to ban the airing of junk-food ads on children's television programs, it got its head handed to it. The agency was derided as "the national nanny," and the U.S. Congress threatened to shut it down if it persisted in its anti-advertising campaign.

That was 25 years and billions of calories ago. But the whole history came back to me recently as states and localities started to weigh in on the latest public health crisis: obesity. It's a problem that's been played up a lot in the press in the past few months and, not surprisingly, a recent poll released by the American Cancer Society and Trust for America's Health found that Americans now rank obesity as the third-biggest health concern--right after the flu epidemic and cancer.

Their concerns are warranted. The country as a whole has gotten fatter, with three times the number of obese children as a generation ago. Moreover, more than a quarter of adults are obese, according to a 2002 study by the federal Centers for Disease Control and Prevention. In state-by-state rankings, West Virginia and Mississippi residents tip the scale as the heaviest; Colorado's population is the leanest.

Crisis though it may be--and certainly, the growing number of overweight schoolchildren is a cause for alarm--obesity is a health problem like few others. There are no vaccinations to give; no tests that can pick up early indicators of the condition. It's not a question of a mosquito-borne virus or contaminated water or unhealthy air--the kinds of things governments can and do take action to control or ameliorate. For the most part, obesity is dependent on human behavior of a most personal kind: how much and what we eat; how often and how intensely we exercise.

And that raises the question of whether this is a health problem that calls for governmental action. The line for the FTC's junk-food campaign was tenuous: The agency had children's welfare in mind but, politically, few at that time saw the tie-in as strong enough for the type of intervention the agency advocated.

This time around, though, there is a difference. In addition to their constituents' well-being, states and localities have a fiscal link--an increase in health-care costs since obesity often leads to such chronic illnesses as diabetes, heart disease and several types of cancer. Medicaid and the State Children's Health Insurance Program are directly impacted by that increase in morbidity. A study published recently in Obesity Research found that states can trace 11 percent of their Medicaid costs to obesity and 5 percent of their overall medical costs to weight problems. In addition, health insurance premiums-- those that governments pay on behalf of their employees and those the private sector offers--also are affected by the increase in disease.

Clearly, states and localities have what lawyers would call "standing" on the issue, and several jurisdictions have begun to experiment with ways to attack the problem. The most obvious is the removal of high-calorie soft drinks and high-fat fast foods from school vending machines and cafeterias. A few school districts around the country have begun taking such measures, and several state legislatures are looking at how to encourage schools to limit vending- machine selections--as well as to increase physical and nutrition education in the schools. Oklahoma's legislature, for instance, will be taking note of a poll taken in December that showed two-thirds of Oklahomans want soda and candy-carrying vending machines removed and that 84 percent want physical education to be a school requirement.

Arkansas, with 24 percent of its population considered obese--a figure that ranks it as the 6th fattest state in the CDC study--is going further. Governor Mike Huckabee, who lost 75 pounds in the past year, and Fay Boozman, his health director who lost 50 pounds, have put together an initiative to attack the health situation through preventive measures and an insurance plan that would provide incentives for healthy lifestyles. The plan is still in draft form, but among other things, it would offer cash benefits to state employees who lower their blood sugar and cholesterol levels or lose weight.

Denver--capital of a state where only 17 percent of the population is obese--is looking more to exercise than diet. It is engaged in what the state's chief medical officer calls "the grand experiment." A new planned community is being developed on the grounds of the old Stapleton airport, an area that sits in the middle of a racially and economically diverse section of the city. The community's design enforces an active lifestyle: lots of parks and trails as well as more reliance on walking to work or taking mass transit. There will also be a flagship health clinic that will emphasize prevention of disease through nutrition counseling and exercise programs.

So far, as governments expand their efforts to reduce obesity, I'm not hearing any mumblings about nannies--national or otherwise.