When does a movement that once seemed reasonable begin to slip its moorings?

When First Lady Michelle Obama began her campaign against obesity, I thought: Yeah, seems like a good idea. Get the kids outside and, by all means, limit their intake of sugar water, er, soda. But worrisome signs were there from the beginning, evident in the campaign against cigarettes.

The health reasons were valid, no denying. But the effort was freighted with an extraordinarily high snottiness quotient. Antismoking neurotics would stage phony coughing fits if a guy across the street lit up.

The world is full of people who Know How You Should Live, and they're always looking for excuses to advise you on your errors. All that self-righteous preaching about the evil weed almost made me want to start smoking again.

The antitobacco movement largely succeeded, and it showed how the same approach can be applied to other behaviors. Soon, you had New York Mayor Michael Bloomberg ranting about trans fats and sodas, and yeah, the health reasons are there, but c'mon. This is the government, telling you how to live right down to ounces of consumption.

Anybody see a problem here? Slippery slope, anyone?

Bloomberg's latest obsession is sweets in the hospitals. The other day he announced a campaign to have sugary and fatty foods eliminated from all hospitals, public and private. It's supposedly "voluntary," but this bandwagon has momentum. "If there's any place that should not allow smoking or try to make you eat healthy, you would think it'd be the hospitals," Bloomberg said.

Notice the choice of words. Mayor Mike wants to "make" you.

Now the harvest of Michelle Obama's work is being rolled out in the form of federally acceptable menus under the Healthy Foods Act. The kids and the moms are not amused.

In Greeley, Colo., the school district has outlawed all sweets, including cupcakes, candy bars and yes, birthday cakes.

Ah, there's an exception. The kids can have cake in school if mom follows a district-approved recipe. But school fundraisers, even those off-campus, may not include sweets. For fundraisers on school grounds, no food items of any kind are allowed.

Think about that. We've gotten to the point of government-approved cake recipes.

The feds, in their wisdom, also have decreed calorie maximums for school lunches -- 650 for elementary school students, 700 for middle-schoolers and 850 for kids in high school -- a standard one teacher, Brenda Kirkham of Sharon Springs, Kan., called "ridiculous" for student athletes who work out three times a day and do farm chores.

Supporters of this crusade tell me not to worry. The slippery-slope risk is exaggerated. Besides, the nation faces an obesity crisis, and all these government functionaries with their one-size-fits-all rules have our best interests at heart.

But in a matter as personal as what we eat, how much trust should we put in people who don't trust us?