BOSTON (Reuters) - For the first time in generations, Americans' average life expectancy could shrink because of an obesity epidemic sweeping the United States, researchers said on Wednesday.
In an analysis that weighed in on the debate over reforming Social Security, health experts concluded that the nation's steady rise in longevity may end in coming decades as more people die early from obesity-related health problems like heart disease, diabetes and kidney failure.
Led by Jay Olshansky of the University of Illinois in Chicago, the researchers said obesity among adults rose by 50 percent per decade during the 1980s and 1990s to the point that nearly one in three Americans is now obese.
The team suggested the methods used to establish life expectancy -- long based on historic trends -- must be reassessed in light of the growing population of obese Americans.
A review is particularly important as obesity rates surge in children and young adults, they said.
More than 9 million U.S. children are obese. Not only do they risk being fat all their lives, doctors say, but they have a higher than average risk of heart disease and diabetes.
"We can compare the childhood obesity epidemic to a massive tsunami heading for the United States," said co-author David Ludwig of Children's Hospital in Boston. "By the time you see the waters rising from the shoreline, it's too late to take protective action. We know that that wave is coming."
WEIGHING IN ON SOCIAL SECURITY
At a time when Social Security reform is consuming U.S. politics, the researchers noted that the question of longevity is not just academic but has major public policy implications.
The Social Security Administration has estimated that life expectancy in the United States will continue to rise steadily, reaching the mid-80s later this century.
The Olshansky team called this projection flawed because it did not factor in the health consequences of being overweight.
The researchers also cast doubt on White House warnings that the retirement program is headed for bankruptcy because of strains from the retirement of the huge baby boom generation.
"Dire predictions about the impending bankruptcy of Social Security based on the SSA's projections of large increases in survival past 65 years appear to be premature," the researchers said in the study, published in The New England Journal of Medicine.
They said Americans may be inadvertently "saving" Social Security by becoming obese, but there will be a heavy price in terms of higher death rates and escalating health care costs.
The United States spends between $70 billion and $100 billion each year to treat health problems linked to obesity.
In a Journal editorial, Samuel Preston of the University of Pennsylvania said the Olshansky team's projections may be "excessively gloomy" because many Americans have adopted healthier lifestyles by quitting smoking, cutting cholesterol, and practicing safer sex, for example.
Still, he acknowledged that failure to address the problem of obesity could dampen "improvements in longevity that are otherwise in store."
In Washington, Iowa Sen. Tom Harkin cited the study's findings as he introduced new legislation that would allow the Department of Agriculture and the Federal Trade Commission to regulate junk food marketing to children.