Among the contentious food issues to be addressed by public policy this year is obesity, which affects Americans of all ages. It occurs in 12.4 percent of children ages 2 to 5, 17 percent of those ages 6 to 11 and 17.6 percent of those ages 12 to 19. It takes a toll on the joints, is associated with several risk factors for cardiovascular disease (including high blood pressure, abnormal lipid patterns, and Type 2 diabetes), and is linked to cancers of the esophagus, breast, uterus, colon, rectum, kidney, pancreas, thyroid, and gallbladder.

Is curbing obesity primarily the responsibility of the government? The self-appointed food police think so, and they are not shy about making their views known. Along the way, their extreme rhetoric demonizes big food producers and characterizes food marketers as little better than child molesters. They’ve even made the counterintuitive claim that First Lady Michelle Obama is a corporate shill and her “Let’s Move” campaign is a publicity stunt, intended to distract the public from what they think are better, more aggressive solutions.

Weighing in from the (far) left are regulation-obsessed activists like Dr. Yoni Freedhoff of the University of Ottawa. He blames the obesity epidemic on public health officials’ and lawmakers’ failure to “legislate change”—not enough statutes, regulations, public monies spent, or taxes on foods he thinks are bad. He believes that because industry is so good at doing its job—which is to “misinform consumers” in their quest to profit from selling as many cheap calories as possible—government needs to intervene.

His fiery YouTube video, which has drawn more than a quarter of a million views and was the basis of a headline in the Los Angeles Times, rallied activists to campaign for more government regulation of what he considers the primary cause of obesity: under-regulated corporate peddlers of cheap calories.

The food police even condemn Mrs. Obama’s attempts to encourage exercise and better diets in order to reduce obesity. Critics like Freedhoff dislike her approach because it recognizes the major role that voluntary choices play in weight control. They dismiss the notion of individual freedom or personal responsibility, and thus omit the most important part of the equation: the consumer. Their views might provide fodder for viral videos but lead to lousy—and tyrannical—policies.

Mrs. Obama’s major initiative as First Lady, the reduction of obesity, gets mixed reviews from various quarters but her attempts at suasion have enjoyed some modest successes:

—Walmart has lowered the cost of fruits, vegetables, and whole grain products, and has pledged to assist manufacturers to reduce by 10 percent the amount of sugar they sell by 2015.

—Darden Restaurants, which owns Olive Garden, Red Lobster, and other chains, has voluntarily changed their kids’ menus to include a choice of a fruit or vegetable and low fat milk with every meal.

—The country’s largest food manufacturers have pledged to cut 1.5 trillion calories from the food they sell by 2015.

On the other hand, the First Lady also championed a 2010 child nutrition law that lets federal bureaucrats decide what kinds of foods may be sold on school grounds, including in vending machines and at fundraisers. She took credit for changes to school lunch programs that left students hungry and protesting. Eventually, the USDA was forced to reverse course.

This is the kind of government intrusion (excessive, in our view) that food police activists like, but it hasn’t mollified them. In an op-ed last year, attorney Michele Simon, an Oakland, California-based leader of the nanny-state movement, criticized Mrs. Obama’s Let’s Move accomplishments as “public relations gestures” that are woefully inadequate to fight obesity. In a broadside against the campaign, she wrote, “negotiated deals with the likes of Wal-Mart cannot become a substitute for actual policymaking.” According to the activists, you can’t make progress in the war against obesity as a partner with industry because they are the enemy, and a powerful one at that.

At the top of the food police’s wish-list are restrictions on the advertising of foods they don’t want people to eat. As Freedhoff puts it, “We need to stop allowing the food industry to target our most vulnerable and precious population, our children.” National Action Against Obesity founder Meme Roth is less subtle in evoking images of child molestation by referring to food advertising to children as “predatory” and arguing that we shouldn’t let food company executives have a “relationship with our kids.” In their zeal to advance an unpopular and tyrannical agenda, it’s the food police who have become the real creeps, spouting rhetoric that verges on hate speech.

Anti-obesity crusaders like to deride as “junk food” whatever they’ve decided is “bad.” But when eaten in moderation as part of a balanced diet, there really is no such thing. Some activists seem to equate the consumption of foods they dislike to smoking, but they are not equivalent. A ban on advertising of tobacco products to kids is appropriate because their use in any form and at virtually any level is injurious. But any nutritionist worth his sodium chloride will confirm that your grandmother was wise in telling you just to do things in moderation.

Yet “moderation,” “personal responsibility,” “parenting,” and even “exercise” are inconvenient concepts to uncompromising activists like Simon, whose website, appetiteforprofit.com, deems corporate profits the underlying cause of obesity.

There is, indeed a role for government policy making, but it’s not intrusive, punitive, arbitrary regulation; it’s allowing market forces to stimulate the production of fresh fruits and vegetables so that they become cheaper and more available to greater numbers of consumers. A major obstacle to that strategy is the many federal policies that prevent the kind of innovation that could give us higher farm yields and lower prices.

These policies include subsidy-driven incentives to grow commodity grains instead of fresh fruits and vegetables, import restrictions that drive up prices, and restrictions on agricultural technologies that could raise yields. And in recent years, federal officials have pushed farmers and retailers to adopt organic and other costly practices that may make consumers feel good about the foods they buy but which in reality are not better for them or the environment.

One of the most egregious of these policies is USDA’s approach to the genetic improvement of plants. For 25 years, the USDA’s Animal and Plant Health Inspection Service has imposed unscientific, excessive, and expensive field test design for plants crafted with the most precise and predictable techniques of genetic engineering. As a result, field trials with these plants are 10-20 times as expensive as experiments with virtually identical plants modified with older, less precise, less predictable techniques; therefore, only a small fraction of potentially important plants developed in university and corporate laboratories ever make it into field trials. (And even fewer make it to the supermarket.)

An article published in 2010 in the journal Nature Biotechnology concluded that over-regulation of genetic engineering “has resulted in lost societal benefits due to foregone innovations that are estimated to be in the billions of dollars.” And a 2009 paper in AgBioForum made these somber observations: “The resulting regulatory environment has delayed and eliminated the introduction of many new technologies and products. The foregone benefits from these otherwise feasible production technologies are irreversible, both in the sense that past harvests have been lower than they would have been if the technology had been introduced and in the sense that yield growth is a cumulative process of which the onset has been delayed.” Economists would say this is a situation marked by the huge opportunity costs of unscientific, excessive regulation.

And yet, far from making the oversight of genetically engineered plants more scientific and risk-based, USDA bureaucrats have tried repeatedly to double down—to make regulation even more unscientific and unsupportable.

To make matters worse, the EPA’s unscientific and excessive regulatory policies have virtually eliminated the once-promising development of “biorational” pesticides that could supplant chemicals. Likewise the EPA discourages innovation by imposing unscientific and excessive regulation on crop and garden plants genetically engineered with state-of-the-art techniques to enhance pest or disease resistance.

Incredibly, the EPA regulates such plants as pesticides and subjects them to even more stringent regulation than the deadly chemical poisons used to kill vermin, viruses, fungi, or bacteria. At the same time, plants engineered withless precise and predictable genetic techniques are exempt from EPA review, no matter what hazards they may pose to human health or the environment.

Thus, federal regulatory policy perverts the fundamental principles of regulation and common sense and inhibits innovation. All of society suffers.

The adoption of scientifically sound, risk-based regulation of genetic engineering by the USDA and the EPA could transform the current trickle of commercial products into a torrent. The result would be the founding of new companies, the appearance of new products, and the creation of new jobs and wealth—as well as lower prices and greater availability of healthful fresh fruits and vegetables. These are the kinds of changes we need in order to tackle obesity, not the activism of those who advocate a nanny-state.