Thursday, March 17, 2005
Overall impact is greater than all accidents, homicides and suicides, researchers say.
SCRIPPS HOWARD NEWS SERVICE
Live fat, die younger.
That's the conclusion of a new analysis by researchers, who say that steadily lengthening life spans for Americans over the past century may be cut short by as much as five years within the next several decades due to the "obesity epidemic."
"Some may view this as pessimistic, but in fact it is a realistic assessment of where we appear to be headed," said S. Jay Olshansky, professor of epidemiology at the University of Illinois-Chicago School of Medicine and lead author of the study, published today in the New England Journal of Medicine.
Olshansky and colleagues calculate that obesity throughout the population currently reduces life expectancy by four to nine months -- already a bigger effect than all accidents, homicides and suicides.
Dire forecast
They predict that the rapid rise in obesity among children and teenagers in the past 30 years will have even greater life-shortening effects in the future, eventually even exceeding the current impact of cancer and heart disease on mortality and perhaps offsetting advances in medical technology.
The researchers argue that current life-expectancy tables use historic trends to project that past increases in life expectancy will continue indefinitely. They compare this to "forecasting the weather on the basis of its history. Looking out the window, we see a threatening storm -- obesity -- that will, if unchecked, have a negative impact on life expectancy."
By calculating years of life lost due to obesity and combining that with estimates of the prevalence of obesity in younger generations, the researchers were able to illustrate that the risk of death from obesity-related causes is about to rise.
"This work paints a disturbing portrait of the potential effect that lifestyles of baby boomers ... could have on life expectancy," said Richard Suzman, associate director for behavioral and social research at the National Institute on Aging, which was a sponsor of the study.
Shorter lives
Suzman says that obesity may already be taking a toll, noting that sharp increases in obesity among people now in their 60s may be one explanation why gains in U.S. life expectancy at older ages have been less than those of seniors in other developed countries in recent years. More than 20 other developed nations have a higher average life expectancy than the United States. Women in Japan, for instance, live an average of five years longer than women in America.
Studies indicate that two-thirds of American adults are either overweight (with a body weight adjusted for height, or body mass index of 25 or more) or obese (BMI of 30 or more).
Body weight is affected by many genetic, psychological and environmental factors that influence diet and activity levels, said Dr. David Ludwig, director of the Obesity Program at Children's Hospital in Boston and a co-author of the study.
He said fast food, sugar-sweetened drinks and low-quality junk food have been major contributors to obesity, as have cutbacks in funding for regular, mandatory physical education in schools and limited health coverage for obesity prevention and treatment.
Prevention
Dr. Ludwig warned that unless better measures are developed to reduce childhood obesity, children today may live less healthy and shorter lives than their parents. "The rapidly escalating prevalence of childhood obesity and its most feared complication, type 2 diabetes, raises the prospect of heart attacks becoming a common condition of young adulthood."
But Olshansky added that the obesity problem "can be fixed" and the study is intended to alert the public to the stakes and the need to support treatment and prevention. "If we succeed, our predictions will be wrong. And that's what we hope."