The worthies who govern Massachusetts haven’t been able to keep the state’s population from dwindling, its property taxes from soaring, its budget from imploding, its Big Dig from leaking, or its politicians from getting arrested. But failure hasn’t diminished their ambition - or their presumption: Now they’re going to keep the rest of us from overeating.

On Thursday, Governor Deval Patrick’s administration launched Mass in Motion, a new war on obesity that it calls “the most comprehensive effort to date to address the serious problem of overweight and obesity in the Commonwealth.” Already up and running is a shiny new website, which appears to consist mostly of trite exhortations to eat sensibly and do more exercise. Needless to say, the administration plans to spend money on its crusade, current budget straits notwithstanding. After all, if the state doesn’t pump $750,000 into such “wellness initiatives” as “expanding the availability of farmers’ markets” and designing “transportation systems that encourage walking,” who will?

But the heart of the new campaign, as with most government initiatives, is coercion. Following the lead of California, New York City, and Seattle, Massachusetts officials plan to compel restaurant chains to conspicuously post the calorie content of all their offerings, either on the menu or at the counter. Obesity warriors want restaurants to be forced to publicize the nutritional content of the foods they sell so that consumers can make a reasoned decision about what to eat. “People often really are not aware of what’s sitting on their plate,” the director of Boston Medical Center’s nutrition and weight management program, Dr. Caroline Apovian, told The Boston Globe. “But if the information is sitting right in front of you … it’s hard to deny.”

Actually, not that hard. When it comes to nutrition as to so much else, human beings are quite adept at denying, ignoring, or discounting information they would rather not deal with. A 2006 study by researchers at the University of Vermont found that the more often one eats in fast-food restaurants, the less likely he is to pay attention to food labels. “These … data suggest,” they concluded, that “recent legislation advocating for greater labeling of restaurant food may not be particularly effective.”

Is it really the job of the state to coerce restaurants into confronting diners with information most of them aren’t interested in? The food-service industry is exceptionally competitive and highly sensitive to customer preferences; if enough diners wanted to look at obtrusive calorie charts when eating out, restaurants would already be providing them. Jacob Sullum of Reason magazine puts his finger on it: “A legal requirement is necessary not because diners want conspicuous nutritional information but because, by and large, they don’t want it.”

Nanny-statists find it easy to disregard consumers’ wishes. After all, they reason, it’s for their own good - obesity is a deadly scourge that government must not ignore. Massachusetts Public Health Commissioner John Auerbach warned darkly last week that “unless we make progress” - that is, unless the government imposes new restrictions on liberty - “overweight and obesity will overtake smoking as the leading cause of preventable death in Massachusetts.”

That always seems to be the nannies’ bottom line, whether the risk is said to be from tobacco, global warming, or cars without airbags: We must take away some freedom or more people will die.

But what will the government do when mandatory calorie information in chain restaurants doesn’t make a dent in obesity rates? Extend the mandate to all restaurants regardless of size? To supermarket display shelves and freezer sections? Will warning labels be required on packages of Oreo cookies and Oscar Mayer hot dogs? Will new regulations prohibit fast-food restaurants and confectioners from running ads on TV or in magazines? And if our collective waistline still doesn’t shrink, will the most fattening foods be permitted only to consumers with a government-approved body-mass index? Or simply banned altogether?

For at least 30 years, the food industry has been labeling packaged foods with nutritional information; with the rise of the Internet, Americans have access to more such information today than ever before. Yet Americans are also fatter than ever before.

Hectoring people about calories doesn’t usually make them thinner. It doesn’t work when family members do it. It won’t work any better when regulators do it. Not even in Massachusetts.