Today, one in three Americans are obese, a rate that has grown steadily across the country for more than two decades. But recent reports show the U.S. health care system is ill prepared to properly care for these folks, who are also poorly served by dismissive doctors, The New York Times reports.

Some of the difficulties faced by more than 5 million extremely obese Americans range from scales and scanners that aren’t built big enough for heavy people to surgeons and doctors who categorically refuse to prescribe certain medical procedures, such as hip or knee replacements, for people they deem too heavy for treatment.

Recent research showed that doctors may spend less time with obese patients and are less likely to refer them for diagnostic tests. One study that asked 122 primary care physicians in Texas about their attitudes toward obese patients found that the doctors considered heavier individuals to be “a greater waste of their time” and “more annoying” than other patients.

What’s more, findings showed these biases can lead to lapses in treatment. For example, cancer studies showed obese patients tend to have worse outcomes and a higher risk of death. Part of the reason for these disparities is not only the lack of medical equipment designed to treat obese people, but also the problem of determining proper drug doses for overweight or obese patients. (Drug dose determinations are usually based on the body sizes of people who aren’t obese and thus may not be right for heavier patients.)

In addition, overweight or obese people may not receive the medical care they need because of their weight. A recent survey of more than 700 hip and knee surgeons found that up to 62 percent of them used body mass index scores as cutoffs for requiring weight loss before offering their patients surgery. Plus, doctors may attribute certain symptoms, such as shortness of breath, chest or back pain, as obesity-related, when these signs could reflect underlying health issues.

“Physicians need better education, and they need a different attitude toward people who have obesity,” said Louis J. Aronne, MD, a specialist in the disease at Weill Cornell Medicine in New York City.

Recently, Aronne helped found the American Board for Obesity Medicine to address this sort of issue. He stressed that doctors need to recognize that obesity is a disease like diabetes or any other illness that requires treatment.

Experts warned that physicians’ biases against obese people and their lapses in care for these patients often make them less willing to visit the doctor for serious health issues or to seek medical care that could eventually help these folks pare off pounds.

Click here to learn more about why fat shaming doesn’t work for obese patients.