Very obese people are as unhealthy, and probably as likely to die, as patients with heart failure, U.S. researchers reported on Sunday.

A second study presented at a meeting of the American Heart Association in New Orleans found that overweight men spend more on drugs than those of healthy weight.

Both studies illustrate the burden that obesity places on health.

Dr. Peter McCullough of William Beaumont Hospital in Royal Oak, Michigan and colleagues compared 43 patients who were morbidly obese to 235 heart failure patients and 222 people who were obese but not extremely so.

The morbidly obese patients were more than 100 pounds (45 kg) overweight. “These are people who weigh 300 to 400 pounds,” McCullough told a news conference.

“On average they die 15 years earlier than individuals of normal body weight.”

Heart failure is a chronic condition in which the heart gradually loses its ability to pump blood properly. Half of all heart failure patients die within five years.

McCullough’s team measured the ability of all three groups to breathe and use oxygen.

“The average middle-aged man should achieve 30 milliliters per kilogram a minute,” McCullough said. A regular exerciser can breathe 55 milliliters per kilogram of body weight.

Morbidly obese men averaged a peak oxygen consumption of 18.8, similar to the 16.5 achieved by heart failure patients.

The healthy but overweight volunteers scored 21.3.

“Individuals who are morbidly obese have a cardiorespiratory fitness ... that is similar to patients with terminal heart failure,” McCullough said.

They are less likely to survive a bad infection or heart attack. But a little light exercise is likely to go a long way to helping the morbidly obese get healthier, McCullough added.

Tnhoma Allison and colleagues at the Mayo Clinic in Rochester, Minnesota found overweight men spend more on drugs.

In their study of 328 male executives with an average age of 47, the healthy-weight men spent an average of $22.84 a month at the pharmacy, overweight men averaged $39.27 a month and obese men spent $80.31.

“These are what we call ‘real and immediate costs’,” Allison said in a statement.