Contra Costa (California) County supervisor Mark DeSaulnier needs to go on the zoning diet — he’s clearly power-hungry. DeSaulnier seems to have taken a cue from other politicians further south, proposing Tuesday that the county study ways to restrict the number of fast-food restaurants. His justification, of course, is that this dire measure is needed to fight the Black Death of our time — childhood obesity. So goodbye to your local restaurant. The government knows what’s best for you.

It’s worth pointing out that DeSaulnier owns his own restaurant. And it seems like he might face direct competition with fast-food outlets. The San Fransisco Chronicle placed his establishment in the “moderate” price range. (According to the paper’s review, DeSaulnier’s Caesar salad is “lifeless” and he offers “a brownie and ice cream concoction” for dessert “that could have served three.”)

Of course, as anyone who eats food should realize, zoning restrictions aren’t going to slim anyone down. A study published in the International Journal of Obesity in 2005 found “no relationship between availability of eating places and prevalence of obesity.”

If politicians really wanted to fight childhood obesity, perhaps they should spend more time getting tough on crime. According to a study in the latest issue of the Archives of Pediatrics & Adolescent Medicine, children living in the least safe neighborhoods are almost four-and-a-half times more likely to be overweight than children in the most safe neighborhoods. This phenomenon occurs regardless of a family’s wealth, too. “Measures of socioeconomic status,” the study noted, “did not eliminate the observed association between perception of neighborhood safety and overweight.” This confirms a pretty basic intuition: When it’s unsafe for kids to go out and play, they stay inside and watch TV or play video games.

Childhood obesity is a genuine problem. But that’s no reason to tolerate politicians who use it to promote pocketbook obesity.