By Emily Miller
Adults with extreme obesity have increased risks of dying at a younger age from cancer and chronic health conditions than their healthier counterparts, according to a recent study.
The study, led by researchers from the National Cancer Institute (NCI), part of the National Institutes of Health, found that people with class III – or extreme – obesity had a dramatic reduction in life expectancy compared with people of normal weight.
“Prior to our study, little had been known about the risk of premature death associated with extreme obesity,” said Cari Kitahara, PhD., Division of Cancer Epidemiology and Genetics, NCI, and lead author of the study.
Based off data discovered during the study, individuals with extreme obesity are more likely to die prematurely from heart disease, stroke, diabetes, and kidney and liver diseases.
Individuals will also experience higher health insurance premiums, as their conditions require additional care and are at a greater risk against the insurance company.
“While once a relatively uncommon condition, the prevalence of class III, or extreme, obesity is on the rise,” said Kitahara in a press release. “In the United States, for example, six percent of adults are now classified as extremely obese, which, for a person of average height, is more than 100 pounds over the recommended range for normal weight.”
Researchers in the study classified participants according to their body mass index (BMI), which is a measure of total body fat. NIH provides a BMI calculator here.
BMI classifications are:
· Underweight: 18.5 and under
· Normal weight: 18.5 to 24.9
· Overweight: 25.0 to 29.9
· Class I obesity: 30.0 to 34.9
· Class II obesity: 35.0 to 39.9
· Class III obesity: 40.0 or higher
The NCI conducted 20 studies that included individuals from the United States, Sweden and Australia. Participants who had ever smoked or had a history of certain diseases were excluded.
Researchers evaluated the risk of premature death overall and the risk of premature death from specific causes in more than 9,500 individuals who were class III obese and 304,000 others who were classified as normal weight.
The researchers found that the risk of dying overall and from most major health causes – mainly heart disease, cancer and diabetes – rose continuously with increasing BMI within the class III obesity group.
Years of life lost ranged from 6.5 years for participants with a BMI 40 to 44.9 to 13.7 years for a BMI of 55 to 55.9.
To put this into perspective, researchers found that the number of years lost due to class III obesity was equal, if not higher, than that of current cigarettes smokers who had a normal BMI.
“Given our findings, it appears that class III obesity is increasing and may soon emerge as a major cause of early death in this and other countries worldwide,” said Patricia Hartge, Sc.D., Division of Cancer Epidemiology and Genetics, and senior author of the study
