New research seems to contradict the idea that people might escape the health hazards associated with obesity if they're "fat but fit."

The new study suggests that the health benefits of physical fitness are offset by obesity. No matter their fitness level, normal-weight men had a lower risk of dying during the study than did the most physically fit obese men, the researchers said.

Still, it's important to note that the study wasn't designed to prove a cause-and-effect relationship. This type of study can only show a link between physical fitness and the risk of premature death.

Findings were published in the Dec. 20 issue of the International Journal of Epidemiology.

The study included more than 1.3 million Swedish men. Their health was followed for an average of almost 30 years, according to the researchers, led by Peter Nordstrom from Umea University in Sweden.

To measure aerobic fitness, the men rode an exercise bicycle until they were too tired to continue.

The men in the top 20 percent of aerobic fitness had a 48 percent lower risk of death from any cause during the study period compared with those in the bottom 20 percent, the investigators found.

However, the beneficial effects of physical fitness decreased as obesity increased, the researchers said. And, for the most obese, even the highest levels of physical fitness couldn't provide health benefits to offset the risks from obesity.

The study authors concluded that being "fat but fit" still poses health risks.