Obesity Rise Trumps Smoking Decline
Study: Life Expectancy Rise in U.S. to Slow
WebMD News Archive
Dec. 2, 2009 -- Over the next decade the health benefits achieved because
fewer Americans are smoking will be more than overshadowed by the negative
health effects of the unchecked rise in obesity, new research suggests.
As a population, Americans are smoking less but weigh more than they have in
According to the CDC, about 34% of U.S. adults, or 72 million people, are
obese today, compared to about 15% in 1980.
But half as many adults smoke. About 1 in 5 American adults smoke today,
compared to 2 in 5 in the 1970s.
Although these competing trends have been obvious, the net impact on health
has been less so.
In an effort to forecast the effect of the rise in obesity and decline in
smoking on health at the population level over the next decade, researchers
from Harvard University and the University of Michigan examined data from
national health surveys conducted from the early 1970s through 2006.
Their study appears in the Dec. 3 issue of the New England Journal of
In every scenario tested, the researchers found that the negative health
impact of not addressing the obesity epidemic outweighed the benefits derived
from the decline in smoking.
No Smoking, Obesity = 4 Extra Years
If all adults in the United States stopped smoking and achieved a normal
weight by 2020, the life expectancy of an 18-year-old would increase by nearly
four years, according to the forecast.
“The hypothetical scenario in which everyone is a nonsmoker of normal weight
by 2020, though, perhaps not achievable, illustrates the dramatic toll these
behavioral risk factors can take when combined,” lead researcher Susan T.
Stewart, PhD, and colleagues wrote.
If past trends continue, nearly half of adults in the U.S. will meet the
World Health Organization criteria for obesity by 2020, the forecast
Better management of chronic conditions closely linked to obesity, including
heart disease and diabetes, would also change the forecast, the researchers
They conclude that efforts to improve health in the United States at the
population level must focus on reducing obesity, further reducing smoking
rates, and improving the management of diseases caused by both.
“Inadequate progress in these areas could result in an erosion of the
pattern of steady gains in health observed in the United States since the early
20th century,” they wrote.