When I was a young adult working in one of my first professional, go-to-the-office jobs, I often brought lunch to eat at my extremely not-private desk. An older, portly woman named Gertrude, on more than one occasion, tsk-tsked me for my food choices. Admittedly, I didn’t always bring ultra-healthful foods for lunch. But her criticism made me want to dig in with even greater gusto — and then visit the vending machine, just for good measure.

The point is that nobody likes a nag, and scolding people — or punishing them, or making them feel guilty — for their food choices is as likely as not to backfire. People don’t like being told what to eat or what they shouldn’t eat.

I’ve been thinking about Gertrude today in light of two recent public-health developments. First, just in time to cast a pall on Valentine’s Day, health experts from the University of California, San Francisco are calling for government regulation of sugar. In a commentary (I’m sorry to only be able to provide a link to the abstract, not the full paper) published Wednesday afternoon in the journal Nature, Robert Lustig and colleagues argue that sugar poses as great a risk to public health as alcohol and tobacco and that therefore its use should be restricted.

The commentary spells out how excessive consumption of added sugars — defined as “any sweetener containing the molecule fructose that is added to food in processing” — can harm the human body; from contributing to high blood pressure and triglycerides to causing liver damage, the possibilities extend beyond simply making people fat.

The authors make the case that sugar consumption in the U.S. is excessive and has increased as our access to and liking for packaged, processed foods have risen. They don’t spell out precisely how much sugar is too much; nor do the current Dietary Guidelines for Americans set a limit on how much added sugar (as opposed to the natural sugar inherent in fruits, for instance) we can have.

The authors note that cutting back on Americans’ sugar intake will likely require making it harder, and more expensive, to purchase sugar-containing foods. They of course suggest some kind of tax, and they even go so far as to propose an age restriction for buying sugar-sweetened beverages, with kids under, say, 17, barred from buying sodas. Ending government subsidies of sugary foods could help, too, they write. (They do note, though, that soda tax programs haven’t taken hold or proven useful in lowering people’s soda intake.)

Even as the sugar debate continues, the folks at the vegan-diet-promoting Physicians Committee for Responsible Medicine have attracted attention for their graphic billboards portraying cheese as the food responsible for making us fat. PCRM founder and president Neal Barnard has been quoted as saying that the ideal amount of cheese in our diets would be no cheese at all.

In my humble opinion, the world would be a sad place without cheese. And though I'm no longer a big fan of sweets, I think any effort to restrict access to sugar should be approached with care. Reading the report in Nature practically made me want to pour a bag of plain sugar into my open mouth, in sheer defiance of anyone’s telling me what I can and cannot eat.

This is why I like the federal government’s newish MyPlate program, which is based on the advice in the 2010 Dietary Guidelines for Americans. That document and MyPlate take a positive approach to nutrition advice; they encourage us to eat fruits, vegetables, lean protein and whole grains without telling us to skip sugar, salt and fat altogether. Instead, they gently suggest we cut back on those ingredients. In other words, MyPlate’s not a nag.

Yes, far too many of us are overweight or obese, and many of us may suffer ill health effects from eating too much sugar and/or too much cheese. There’s got to be a way to help people moderate their diets in such a way that they can enjoy foods of all kinds without going overboard.

But my advice to anyone coming up with ideas for what other people should and shouldn’t put in their mouths: Remember Gertrude. If you come off sounding like her, people will surely rebel.