Can someone be fat and healthy at the same time? Researchers say that everyone who’s obese isn’t always unhealthy, and the difference maker isn’t one’s diet — it’s a single protein.

It’s been well-established that obesity triggers a wide array of health problems, from diabetes to heart disease to cancer. So clear is the link between obesity and illness that the American Medical Association voted in 2013 to classify obesity itself as a disease.

Now, however, nutritional scientists have verified a phenomenon, albeit a controversial one, that many of us have witnessed (if we’re paying attention): A small fraction of the overweight population is actually quite healthy.

Despite being significantly overweight, these people have normal blood sugar levels. Their resting blood pressure is within normal limits. By all of the typical measurements taken during a routine physical exam, they’re healthy, even though they may be classified as clinically obese.

Now, according to a new report in Science magazine, researchers have identified a single protein that may determine whether obesity is harmful or benign.

Actually, that’s not quite correct. It’s not either/or, it’s more of a continuum, with the emerging consensus being that “healthy obesity” is but a phase. Ravi Retnakaran, an endocrinologist at the Leadership Sinai Centre for Diabetes in Toronto, Canada, was quoted in the Science story as saying that, “Sooner or later, the outliers will develop metabolic syndrome, a condition in which glucose, cholesterol and lipid levels soar, causing diabetes and heart disease.”

Seemingly healthy obese people may already have early signs of disease, which may not show up on routine tests, Retnakaran said. In a 2013 study of more than 14,000 healthy South Korean adults, scientists discovered the early beginnings of plaque build-up in the arteries of obese patients more often than they did in people within a normal weight range.

To determine when the transition from healthy to unhealthy obesity takes place, Harald Esterbauer and fellow researchers at the Medical University of Vienna analyzed a protein called heme oxygenase-1 (HO-1), which is thought to suppress inflammation, the critical development in obesity that is linked to disease. When the pancreas, which produces insulin, is exposed to elevated levels of nutrients, such glucose, typically associated with overeating, it becomes inflamed and begins to deteriorate, which decreases insulin secretion and can lead to the developoment of Type 2 (adult onset) diabetes.

A potent little protein

In studying the role of HO-1, the researchers found that 27 of 44 obese patients studied showed early signs of insulin resistance, a precursor of diabetes. Insulin responses were normal in the remaining 17 patients. Esterbauer’s team biopsied the tissues from both groups and found that HO-1 levels were twice as high in the insulin-resistant group.

“We believe that HO-1 is a very early marker of metabolic disease,” Esterbauer told Science.

Further research may indeed confirm that the HO-1 protein does catalyze the development of the disease-inducing symptoms associated with obesity. And that may open the door to development of a drug that could “shut off” the action of HO-1, which would be an R&D project eagerly embraced by the major pharmaceutical manufacturers.

With one-third of American adults considered overweight or obese, we’re talking about a potential market that would dwarf the profitability of the drugs currently prescribed for hypertension or hypercholesterolemia — two conditions, by the way, linked directly to obesity.

You think you’re sick of erectile dysfunction ads, a pill that “cures” obesity — at least its ill effects — would trigger a tsunami of television advertising that would make those cell service and car insurance ads seem like refreshing palate cleaners.

But that’s not to suggest that anyone who needs to a shed a few pounds ought to stretch out on the couch with an entire box of Cheez-it and just wait to see what the drug companies develop.

There’s a better way avert the detrimental impact of obesity: Start eating right so you don’t pack on the pounds in the first place.

The opinions expressed in this commentary are solely those of Dan Murphy, a veteran food-industry journalist and commentator.