Obesity epidemic may reduce life expectancy

A study by sociologist Yang Yang shows that American life expectancies may drop in years to come as the obesity epidemic progresses.

American life expectancies, which have climbed steadily for almost a century, may drop in years to come as the obesity epidemic progresses.

Therefore, according to three faculty members from different universities, the National Center for Health Statistics should supplement its lifespan forecasting methods with an additional variable: the health of today’s younger generations.

Their study, “New Forecasting Methodology Indicates More Disease and Earlier Mortality Ahead for Today’s American Children,” is published online and in the August 2011 issue of the journal Health Affairs. Accurate forecasting is essential to wise policy decisions, said the researchers.

“Our analysis shows that health declines and reduced life expectancies will occur without aggressive public health action,” said co-author Yang Yang, an associate professor of sociology at the University of North Carolina at Chapel Hill.

Yang and the other researchers – S. Jay Olshansky, an epidemiology professor at the University of Illinois at Chicago, and Eric Reither, a sociologist at Utah State University – said forecasting now looks at death rates for each age at a given year or years to predict future death rates.

“Traditional forecasting assumes that when today’s children reach the age of 70, they will have the same mortality rate as people who are 70 today,” said Yang, also a member of the UNC Lineberger Comprehensive Cancer Center.

The researchers used the traditional forecasting method to predict cardiovascular disease death rates among men after the year 2000. Then they sought the same information using their new model, which also accounted for the health status of younger populations.

They found their method to be more accurate, correctly predicting an increase in cardiovascular death rates for men between the ages of 25 and 29. This may be because younger men have been more affected by the obesity epidemic than their predecessors.

“We need to think of the health of today’s kids and adapt modeling so that it is sensitized to their health if we’re going to make accurate predictions,” said Reither.

Besides birth cohorts, residence and race may need to be considered. The obesity epidemic has hit hard among women in some areas of the Southeast, African American women, American Indians and Alaskan natives. The authors note that as the population becomes heavier faster, people are living more of their lives with risks associated with obesity, such as Type II diabetes.

“These are not trivial issues without major health and economic consequences for the nation,” Olshansky said. “They are profound. An entire generation of children is in trouble. It’s a problem that can be fixed, but first we have to know the problem exists.  Our methodology enables us to see the problem under the light of science in a rather startling way.”

The study was funded by the University Cancer Research Fund, the Utah Agricultural Experiment Station at Utah State and the MacArthur Research Network on an Aging Society.

Study link: http://www.healthaffairs.org/doi/10.1377/hlthaff.2011.0092