BOSTON -- Ninety-one percent of Americans say they “feel well” and 76 percent “consider themselves healthy,” according to a survey by Health Dialog Services Corp., a provider of health care analytics and decision support.

Two-thirds of Americans are overweight or obese, according to many health reports, a number that many survey respondents seemed to be aware of as 52 percent of them say that obesity is the most widespread health problem in the United States. Despite this, 12 percent of respondents say they do not exercise at all and 20 percent say they exercise for 30 minutes to an hour per week. The U.S. Department of Health & Human Services recommends that adults get a minimum of 2 hours and 30 minutes of moderate-intensity exercise or 1 hour and 15 minutes worth of vigorous-intensity exercise per week.

The survey, commissioned by United Kingdom health care services provider Bupa, was conducted as part of Bupa Health Pulse 2010, a global study of health attitudes and behaviors of more than 12,000 individuals across 12 countries.

Of the 12 countries surveyed, Americans were the most sedentary on a daily basis, with one out of every 10 saying they sit for 12 or more hours each day.

“Americans need a wake-up call,” said Jan Maurer, MD, vice president and medical director at Health Dialog. “People need to realize that lifestyle factors are actually life-and-death factors. With over 50 percent of U.S. health care costs attributable to chronic disease, we literally cannot afford to continue living as we are. Americans must take a good look in the mirror and realize that the ‘they’ are actually ‘we.’”

Globally, heart disease is the biggest killer, and diabetes is the fastest-growing chronic condition. Medical evidence has shown that obesity is a precursor to both.

“Chronic disease is the leading cause of death and disability globally, representing 60 percent of all deaths. What’s concerning is that many of these diseases are preventable,” said Julien Forder, senior research fellow, the London School of Economics, which published the study. “We know from research that exercise is one of the most effective lifestyle changes you can make to reduce your risk of developing long-term conditions.”

He said that 30 percent of cardiovascular disease and 27 percent of diabetes could be avoided if Americans started to exercise.