Eagles running back Boston Scott is officially listed at 5-foot-6 and 203 pounds, giving him a body mass index (BMI) of 32.8. Some sources have him at 5-7, for a BMI of 31.8.

Either way, with a BMI over 30, the star of Monday’s win over the New York Giants meets the definition of being obese.

Not to worry. As Inquirer columnist Mike Sielski once described him, the muscular Scott is “a stack of rocks" — one of several body types for which BMI may not be a good health indicator.

Coined in 1972, the term “body mass index” is defined as a person’s weight in kilograms divided by height in meters squared. Muscle tissue is denser than fat, so someone built like Scott can have a misleadingly high BMI, Penn Medicine endocrinologist Mitchell A. Lazar said.

The index is nevertheless a valuable screening tool, he said.

It is well established that on a population level, a high BMI is correlated with a higher risk of cardiovascular disease and diabetes. For individuals and their physicians, it is one piece of information that can help lead to a diagnosis of genuine health problems, said Lazar, director of the Institute for Diabetes, Obesity, and Metabolism at Penn’s Perelman School of Medicine.

Others for whom BMI is an imperfect indicator include the “fat but fit” — those who have a fair amount of subcutaneous fat (fat beneath the skin) yet are in good cardiovascular shape. Offensive linemen sometimes meet that description, Lazar said. (A high level of belly fat, on the other hand, can spell trouble.)

Then there are the thin but metabolically obese. That includes people with lipid disorders or severe anorexia whose bodies have difficulty storing dietary fat in their fat cells. Instead, they store some fat in the liver or muscles, resulting in insulin resistance and other metabolic dysfunction that can resemble that of an obese person.

Lazar has not examined Scott in a medical setting, but he watched Monday’s game and was impressed by the speedster’s 128 total yards from scrimmage.

Eagles fans have plenty of cause for concern in the waning weeks of the season, but Scott’s BMI is not one of them.

“I’m guessing that this is a result of working out and being in great shape,” Lazar said. “He’s getting put in a bin that’s not really predictive.”