Potatoes aren't glamorous, trendy or sophisticated. They're not charming or prestigious, and when it comes to razzle-dazzle, well, they're about as scintillating as your average rock.

As if the poor vegetable doesn't have enough of an image problem, now Harvard researchers are blaming the lowly spud for making us fat. In a study published in the New England Journal of Medicine in late June, the researchers say that potato chips and French fries are the two most fattening foods.

Dissing potato chips at the height of the back-yard barbecue season, what were the researchers thinking? One thing is for sure: This is something that tater fans won't stomach, no matter how much ketchup is involved.

Sure enough, the report was barely made public before it became a hot potato. Spud buffs quickly shot back that potatoes provide potassium, magnesium and vitamin C, and they argued that any food that is deep-fried in oil that's high in trans fats is going to finish near the top of the calorie chart. (Although if you put the food on a stick, you probably could sell a ton of it at the State Fair. But that's another matter.)

Plus, the critics said, the study didn't establish a direct cause-and-effect relationship. It reported that people who are fat tend to eat more potato chips and French fries than people who are thin. But, the naysayers point out, chubby folks tend to eat more of many foods, especially those of the fattening variety. They ask: How do we know that it's the fries that are making people fat and not the two bacon-cheeseburgers and double-thick milkshake that were consumed with them?

It turns out that the researchers don't have a broad anti-tater agenda. The study, which tracked long-term weight changes, had a fairly narrow focus: If a person ate an additional serving of a specific food every day, which foods would result in the greatest weight gain and which would tend to cause a loss?

Potato chips and French fries ended up on the top of the weight-gain list, followed by sugar-sweetened soft drinks, unprocessed red meats and processed meats. The weight-loss side was led by yogurt, nuts, fruit, whole grains and vegetables.

In a video released with the study, one of the lead researchers skimmed over the potato issue to focus on the foods that led to weight loss, a result the study deduced comes from having less appetite for fattening foods because we've filled up on low-calorie offerings.

In the video, Dariush Mozaffarian, an associate professor at the Harvard School of Public Health, says that the counter-intuitive nature of the discovery -- that eating more of something results in weight loss -- is "a really important message for people. [Weight loss] is not just about eating less of everything. It's actually about eating more of foods that help satiety, that help you feel full so that you eat less of other foods."

But by the time he got to this disclaimer, it was too late. The researchers had kicked sand in the face of Mr. Potato Head, and his legions of admirers were boiling.

The Idaho Potato Commission announced that it's mounting a TV marketing campaign to rebut the potato bashers. The ads are expected to start airing in September. The U.S. Potato Board trotted out a study from the University of California, Davis, that praises potatoes' place in a well-balanced diet. And couch potatoes all over the world took umbrage.

Jeff Strickler • 612-673-7392