From the Hollywood Diet to fusion cuisines, the Golden State often sets health and dietary trends for the other 49. But California’s politicians must have overlooked the health-conscious reputation of their constituents when they voted for SB 120.

This bill—the latest quick-fix diet scheme proposed in the name of public health—assumes that consumers can’t tell the difference between French fries and fruit cups. It would require restaurants to turn their menus into encyclopedias, featuring long lists of nutritional warnings next to every item. For most of us, a back page of fat-and-calorie endnotes would suffice. But the cuisinuts who cooked up SB 120 would rather force consumers to suffer through the informational equivalent of an ice-cream headache before ordering lunch.

Nutrition activists have already tried and failed at the knowledge-equals-behavior approach. In the early 1990s they pushed the government to mandate nutrition information on grocery items, but healthier eating habits didn’t follow. Most people who reported using “Nutrition Facts” to fill their shopping carts were the people who already considered themselves health conscious. Proponents often cite studies based on focus groups or questionnaires. This data comes from asking individuals—in front of several other people—what items they would likely order from labeled and un-labeled menus. Not surprisingly, most publicly boast that they would certainly select the lowest-calorie food.

While people talk a big game in phone surveys and focus groups, few Americans change their eating behavior when faced with a nutritional profile of their food. In the real world, studies show that meal selection is primarily influenced by factors like smell, taste, texture, hunger, cravings, time, and convenience—not diet facts.

Why are California legislators ignoring this losing track record?

Some officials argue that if Governor Schwarzenegger is serious about combating obesity, he should sign this measure into law. But this week a federal judge struck down New York City’s version of SB 120, ruling that it conflicted with federal authority. So menu-labeling diktats aren’t just silly. They’re also illegal.

Besides, the bill only targets restaurants with standardized menus and 15 or more locations. This excludes most of California’s restaurants, including taco stands, sports arenas, and white-tablecloth establishments.

Love-handles don’t distinguish between the calories from a butter-drenched lobster tail and those from fast-food fruit parfait. So if the intent of the legislation is truly to focus on Californians’ weight, it shouldn’t make a distinction either.

While anyone with an IQ above room temperature knows the difference between a bucket of fried chicken and a mixed green salad, most restaurants provide nutrition information anyway. Dieters and picky eaters can already find nutrition facts on posters, brochures, websites, and 1-800 numbers.

There’s a huge difference between personal responsibility and dietary paternalism. Legislators and nutrition activists want to turn personal meals into public affairs, wedging legislation between you and your waistline. Under the new law, calorie counts for every item will be plastered across menus, whether you want them or not. And this will have unintended consequences.

A growing chorus of researchers is cautioning regulators about the collateral damage of programs similar to menu labeling. During the same time that health officials have placed increasing emphasis on obesity rates, the incidence of eating disorders has nearly tripled. As Senator Hillary Clinton put it, “many adolescents misinterpret [the fight against obesity] as a message that they should eat to achieve the body of a runway model. Anorexia and bulimia are increasingly common among our nation’s youth.”

Americans should still have a right to guilt-free eating.