Gains in life expectancy contrast with Americans' unhealthy behaviors, which have led to a 28 percent adult obesity rate, a diabetes rate of nearly 10 percent and a high blood pressure rate of more than 30 percent, according to United Health Foundation's 2012 America's Health Rankings.
All three conditions are considered risk factors for cardiovascular disease.
"As a nation, we've made extraordinary gains in longevity over the past decades, but as individuals we are regressing in our health"Since 1990, premature deaths have declined by 18 percent, cardiovascular deaths have fallen 35 percent, and cancer deaths have slipped by 8 percent, the report said.
Americans' life expectancy was 78.5 years in 2009, 1.7 years above the level in 2000, the report said.
"As a nation, we've made extraordinary gains in longevity over the past decades, but as individuals we are regressing in our health," said Dr. Reed Tuckson, a medical adviser at the United Health Foundation and chief of medical affairs at the UnitedHealth Group.
Among the 24 different metrics involved in calculating the nation's health are a variety of factors such as smoking, violent crime and a lack of health insurance.
The report, now in its 23rd year, incorporates data from the Centers for Disease Control and the U.S. Census Bureau as well as the FBI, among other sources.
Vermont was found to be the healthiest U.S. state thanks in part to a low incidence of infectious diseases, a low violent crime rate and a high rate of health insurance among its residents.
Mississippi and Louisiana were found to be the unhealthiest states because of a high prevalence of obesity, diabetes and a low birth weight among infants, among other factors.