The “cabbage soup diet” forbids everything except water and cabbage. Only the foods that were available to our Paleolithic ancestors are allowed on the “caveman diet.” And the “raw food diet” is pretty self-explanatory.

Taking its cue from these crash diets and the New Year’s resolution to give up all “bad” food (this time for real), the Institute of Medicine has just proposed prohibitive new guidelines for eating in schools.

In the name of fighting childhood obesity, the committee recommends the removal of soon-to-be demonized foods from the school grounds, sorting said items into the bad, the unwelcome, and the downright dangerous. In contrast, physical activity received little more than lip service.

Even though many studies show that students who participate in the National School Lunch Program eat more calories and are more likely to be overweight than those who choose a different lunch, the IOM report gives the almost 30 million meals served daily under the government’s program a “get out of jail free” card.

With federally sponsored french fries and chicken fingers finding sanctuary under heat lamps, it’s the remaining food that gets the blame for all pudgy kids. But the regulations around these other, so-called “competitive” foods — like a bag of Sun Chips or a package of Fig Newtons — seem arbitrary and have little to do with children’s weight.

The IOM committee slipped fruit juice into the “approved food” category with nuts, veggies, and whole grains, even though the sugar and calorie content of juices — often more than a soda — should relegate them to the outlawed “sugary drinks” group if weight loss is really the goal. Conversely, diet sodas, with no sugar or calories, landed on the blacklist for their carbonation and caffeine.

The irony in all this is that almost every piece of research on in-school nutrition indicates that food bans don’t help fight obesity. According to the American Heart Association, kids are becoming overweight well before they are old enough to go to school. Inactivity is the real documented cause of childhood obesity.

Almost 40 percent of school districts have actually eliminated recess. And between 1991 and 2003, enrollment in high school P.E. classes dropped by one third.

What to do?

Walk to school. Break out the push lawnmower. Turn off the TV. Government regulations and top-down solutions to obesity just aren’t going to work. Weight gain is best tackled person by person, family by family.

Spare the kids the hundred-page bedtime story from the IOM. And say instead: “Tag, you’re it.”

Richard Berman is executive director of the Center for Consumer Freedom, a non-profit coalition supported by restaurants, food companies and consumers.