If you’re trying to watch what you eat, French fries are probably on your list of dietary don’ts.

Now here’s another reason to shun those golden-brown spuds… corn oil.

It’s considered one of the less healthy vegetable oils, because it’s high in harmful saturated fats and low in heart-protective alpha-linoleic [linn-uh-LEE-ick] acid.

According to an article published in the journal Proceedings of the National Academy of Sciences, corn oil is commonly used to cook French fries.

In the study, researchers purchased fries from seventy restaurants representing six national fast-food chains.

They also bought samples from a similar number of independent restaurants.

Then they extracted oil from the fries.

By measuring a particular carbon isotope, researchers estimated whether any corn oil was used in cooking the fries.

The results suggested that five of the six fast-food chains used some corn oil. Only twenty percent of the independent restaurants used it.

That’s probably because corn oil is fairly expensive when purchased in small quantities.

The researchers also determined who was frying with oil blends that were at least half corn oil.

Seven percent of chain restaurants fit this category, as did eleven percent of the independent restaurants.

That means, mom-and-pop sandwich that splurge on corn oil sometimes go all-out.

But here’s some good news… previous studies have shown that knowledge of food ingredients can spur better eating habits.

So the next time you hanker for a hamburger and fries, remember the “kernel” of truth from this “corny” study.

Maybe it’ll help you turn a deaf “ear” to the drive-thru’s siren song.