Be warned. Perrier, plastic bags and Grandma’s pot roast are the latest threats to public health.

Sen. Tom Harkin, D-Iowa, may soon try to ban carbonated water from schools, based on recommendations from the Institute of Medicine. Boston, Phoenix, Santa Cruz, Calif., and Portland, Ore., want to follow San Francisco’s lead in mandating “paper only” shopping bags in grocery and convenience stores. And one Virginia municipality has forbidden chari@@hyphen@@ties from feeding home-cooked meals to the homeless — arguing that the risk of food poisoning trumps the hazards from any dumpster diving alternative.

In the name of health, the environment and (most popularly) the children, policymakers are imposing increasingly eccentric edicts on the population. So what’s next?

Two bills in the New York state Legislature (S3787 and A729) — the latest quick-fix schemes proposed in the name of public health — assume consumers can’t tell the difference between apples and oranges (or at least french fries and fruit cups). The bills, discussed in Jennifer Wilkins’ May 6 Food Citizen column, would require certain restaurants to turn their menus into encyclopedias, featuring laundry lists of nutritional warnings next to every item.

Unlike existing labels on mass-produced boxes of cereal, the ingredients for one menu option can be altered a hundred different ways based on the wishes of the chef, the customer or anyone in between. But these bills mandate one blanket calorie count per item, opening the door for lawsuits from trial lawyers as soon as the first heavy-handed waiter gets a little too generous with the Parmesan.

Proponents of the measure — such as sponsors Assemblyman Felix Ortiz, D-Brooklyn, and Sen. Kemp Hannon, R-Nassau County — argue that pushing imprecise, in-your-face warning labels on consumers will spur them to make “better” food choices. However, common sense suggests that a consumer selecting doughnuts over yogurt lacks motivation, not information.

Americans have unprecedented access to information about food. Diet and health books netted about $530 million in sales last year. News anchors report almost daily about the latest studies on weight and nutrition. And myriad Web sites, posters, brochures and toll-free telephone numbers provide a detailed breakdown of menu items at most large chain restaurants — the very same ones that would be covered by this legislation.

But the growing bounty of food facts hasn’t put the brakes on the nation’s growing waistline.

Using the same argument — that more information guarantees healthier choices — food activists in the late ’70s successfully pushed the Food and Drug Administration to require a litany of facts on processed goods in grocery stores. While detailed nutrition labels left their mark on the packages of cookies, chips and ice cream, little changed in the purchasing habits of American consumers.

In fact, former FDA commissioner Lester Crawford admitted that “(America) had mandatory nutrition labeling for 10 years, and the (obesity) situation got steadily worse during that time.”

Multiple studies show that the people most likely to benefit from nutrition facts are those who already consider themselves “health conscious.” But for most other consumers, these labels often cast a halo effect over the lower-fat or lower-calorie items, leading to over-consumption and (you guessed it) weight gain.

So these bills could actually hurt the very same people they are intended to help.

Let’s face it. Most people don’t need detailed charts to tell them that eating a large bag of potato chips isn’t figure-friendly. Similarly, people looking to trim the fat already know to steer clear of the deep-fried-everything joint — regardless of the government-mandated warning signs on the menu.

Averaging less than six hours of sleep a night and brushing their teeth only once a day, Americans often choose not to comply with other principles of good health. So the next step in the name of health may very well be subsidized floss.

It’s time to draw a line in the sand and say, “Here, and no further.” Unless we want government regulators to tuck us in at night, pretty soon we’re going to run out of ways to pretend that the government can make us healthy.

Meanwhile, the activist lobby pushing for caution signs on barbecue ribs pretends that personal responsibility is powerless to prevent someone from eating that fifth taco.

A lot of people get into trouble by ignoring common sense. How is using government to restate the obvious going to help?