Recent predictions that the obesity epidemic will lead to shorter lifespans for today’s young adults are challenged by a new study conducted by Massachusetts researchers, which suggests a more optimistic outlook: The average 25-year-old today can expect to enjoy at least two extra years of a healthy life compared with those a generation ago.
The study, published Thursday in the American Journal of Public Health, used data from six different government surveys conducted from 1987 to 2008 to calculate the “quality-adjusted life expectancy,” which is the number of years Americans can expect to live in good health, free of disease, disability, and mental illness.
Gains in this quality of life expectancy over this two-decade period were 2.4 years for a 25-year-old living today and 1.7 years for someone who is 65 years of age. “It’s incredibly important to know whether people are not just living longer but living better,” said study co-author Dr. Allison Rosen, an associate professor of quantitative health sciences at the University of Massachusetts Medical School. “We’d like to know whether health care dollars spent on treating heart attacks or managing depression could increase not only the length of life but also the quality of life.”
To define the vague notion of high-quality living, Rosen and her colleagues from Harvard University and the National Bureau of Economic Research in Cambridge measured more than a dozen different factors that could destroy a person’s sense of well-being, such as not being able to bend or walk properly, feeling anxious or low energy, or having hearing or vision loss. They also considered smoking and obesity to be risk factors that subtracted from these quality years.
The researchers found an increse in walking problems in adults younger than age 65, while seniors seemed to have fewer problems with walking. Those of all ages had higher rates of obesity but lower rates of smoking in 2008 compared with two decades earlier. They also had less depression and fewer vision and hearing problems.
“I like this study because it opens a new window into measuring quality of life,” said Dr. Jay Olshansky, a professor of public health at the University of Illinois at Chicago, who was not involved in the research. But, he added, it may contradict previous research—including his own—that suggests older populations are living longer and in better health than their parents, while younger adults are slated to live in worse health due to both an increase and earlier onset of obesity.
The results of the new study also do not apply to everyone equally across the board. White women under age 65 had the smallest increases in their quality of life years—1.6 years—while black men under 65 had gained the most, 4 years.
Olshansky’s research suggests that those who have college degrees enjoy the longest life expectancy gains, while those who never graduated from high school have far smaller gains, with some groups even experiencing a decrease in life expectancy compared to the previous generation.
The latest study was not designed to compare life expectancy differences by level of education or other factors shown to make a difference, such as income.