There’s no question that America is faced with multiple health crises, none of which are easy to solve. Two of those – opioids and obesity – have been varyingly suggested as reasons why the US death rates year on year aren’t improving. Although we still can’t be certain, a new study highlights the damaging role of the latter.
For 40- to 84-year-olds, the US has an annual decline in mortality rates of 1.53 percent, but the UK, for example, experienced a 2.45 percent deline. This is comparable to Switzerland, Norway, Finland, and Australia's rate of decline.
Led by the University of Pennsylvania and the Boston University School of Public Health, the team explain that “deaths of despair”, those linked to the opioid crisis – as well as suicide rates, alcohol, and other drug-linked afflictions – can’t explain “why the rate of mortality improvement in the United States has declined relative to other wealthy countries.”
So they took a look at obesity instead.
Obesity is largely defined by the body mass index (BMI), which is a person’s weight (in kilograms) divided by their height, squared. A BMI of 30 or above classifies someone as obese, with higher categories available for more extreme forms of obesity. According to the US Centers for Disease Control and Prevention (CDC), more than a third of adults (36.5 percent) are obese. So could this all-time high be playing a role in declining improvement rates?
Writing in the Proceedings of the National Academy of Sciences, the team explain that they mined their data from the National Health and Nutrition Examination Survey, or NHANES. This nationwide survey combined interviews and physical examinations to provide a broad but detailed picture of the state of Americans’ health.
Comparing these stats to linked mortality files and calculating the role BMI played in changes of circumstances, the team found that rising BMIs has, in 2011 alone, “reduced life expectancy at age 40 by 0.9 years, and “accounted for 186,000 excess deaths that year.” That’s about 510 obesity-linked deaths per day.
Ultimately, between 1988 and 2011, “rising Max BMI is estimated to have slowed the annual rate of mortality decline during this period by 0.54 percent,” which the team note is “a large amount by international standards.”