Life expectancy in the United States is going up, but chronic disabilities, including many caused by bad food choices, smoking, obesity, physical inactivity and alcohol abuse, account for a larger portion of health issues in the United States than in its economic peers around the world, according to a new study by a global collaboration of scientists.

Since 1990, many childhood diseases are less prevalent, and there has been a dramatic reduction in sudden infant death syndrome from 6,000 to 1,500 per year, according to the study. There has also been a significant drop in death and disability from HIV/AIDS, and there are lower mortality rates for people of every age.

But other countries are improving faster. Americans born in 2010 could expect to live 78.2 years, up from 75.2 years in 1990, but that ranked 27th among the 34 nations considered its economic peers. The United States also ranked 27th in high body-mass index, an indicator of obesity, and 29th on blood sugar.

“The United States spends more than the rest of the world on health care and leads the world in the quality and quantity of its health research, but that doesn’t add up to better health outcomes,” said Christopher J.L. Murray, director of the University of Washington’s Institute for Health Metrics and Evaluation, and one of the study’s lead authors. “The country has done a good job of preventing premature deaths from stroke, but when it comes to lung cancer, preterm birth complications and a range of other causes, the country isn’t keeping pace with high-income countries in Europe, Asia and elsewhere.”

“The State of U.S. Health, 1990-2010,” published by the Journal of the American Medical Association on Wednesday, is “a landmark study, the first comprehensive box score of American health that’s been published,” said Howard C. Bauchner, the journal’s editor in chief.

In a related study examining each county in the United States, researchers at the University of Washington found that more people are running, biking and exercising in other ways. But so many others are becoming obese that the increased physical activity has had little effect on the average health of Americans.

The studies were released simultaneously in advance of first lady Michelle Obama’s meeting with U.S. mayors Wednesday, at which she planned to use the results to address her efforts to improve the nation’s diet and exercise habits.

“The good news is these are things we can do something about,” said Thomas R. Frieden, director of the Centers for Disease Control and Prevention. “If you look at the county-by-county charts, it shows in communities where they took improvements in health seriously, they were able to see dramatic improvements.”

The leading cause of death for Americans remains heart attacks, or ischemic heart disease, and the risk factors for that include poor diet, lack of exercise and tobacco use. Fewer people died of heart attacks in 2010 than in 1990, but the rise of other diseases such as diabetes on the list of leading causes of death worries medical professionals.

Frieden noted that the United States is among the last of its economic peers in offering universal health care, and it is late in making societal changes to address the risks that needlessly shorten lives.

“If we want to improve our health, the money is in the heart,” he said. In addition, motor vehicle crashes kill Americans at a rate three times higher than other highly developed nations, he noted, and it’s largely young people who die in them. Finally, prescription drug overdoses is “an epidemic,” Frieden said, far outstripping deaths due to illegal drugs such as cocaine and heroin.

“We need to accelerate prevention,” Frieden said.

Bauchner, who is also a doctor, said that other remaining challenges include worrisome increases in Alzheimer’s disease, opiate use and mental and behavioral disorders.

“We can’t forget that poverty drives health care,” Bauchner said. While increased physical activity is not enough to solve the obesity crisis, he said, the issues surrounding diet are complicated and will take “a herculean effort to transform how we live.”

In 2010, 678,282 Americans died because of dietary risks, the study said, outpacing the 465,651 who died that year of smoking-related diseases. High blood pressure, obesity, physical inactivity, high blood sugar and high cholesterol claimed 1.4 million others.

“If the U.S. can make progress with dietary risk factors, physical exercise and obesity, it will see massive reductions in [premature] death and disability,” said Ali Mokdad, a University of Washington professor who worked on the studies. “Unhealthy diets and a lack of physical activity in the U.S. cause more health loss than alcohol or drug use.”

The “State of U.S. Health” study is the first comprehensive analysis of disease burden in the country in more than 15 years. It said that chronic disabilities in 2010 accounted for nearly half of all life-shortening health issues. Mental and behavioral disorders alone made up 27 percent of what researchers call “years lived with disability,” meaning the time spent in less-than-optimal health. The biggest contributors are depression, anxiety, drug use and alcoholism.

Researchers said they hope communities across the United States will use the online archive, at, to look at their statistics and address their challenges.

“Success stories tell us changes in life expectancies are possible,” Murray said. “Success stories within the country tell us progress can be made. . . . Improving diet, stopping tobacco use and increasing physical activity can work.”

The doctors also acknowledged that pharmaceutical and medical interventions have improved since 1990, citing more widespread use of vaccines that have helped control influenza, statins that address cardiovascular issues and improvements in cancer treatment.

Although communities in the Washington region did not show major increases in physical activity in 2010, several were found to have among the lowest percentages of obesity.

Only 17.6 percent of the women in Falls Church were reported as obese, the lowest percentage in the nation. Men there came in third, behind San Francisco and New York City, with 19.5 percent reported as obese.

The men in Fairfax City and the District also made the top 10 of least-obese communities, with 22 percent and 22.4 percent, respectively.

Men in Fairfax County enjoyed the longest life expectancy in the United States, at 81.67 years. Montgomery County men were not far behind, with the fourth-highest expectancy, 81.57 years. Loudoun County men had the eighth-longest life expectancy, 81 years.

Women in Montgomery could expect to live 84.87 years, the second-longest life expectancy behind Marin County, Calif. Fairfax County women had the fifth-longest life expectancy, at 84.52 years.