Obesity is associated with several serious health conditions including increased risk of diabetes, heart attacks, and cancer. But just how serious is that risk? Serious enough to cut life expectancy by up to 14 years, new research shows.
The research, published in PLOS Medicine, analyzed data from 20 similar studies from the National Cancer Institute. The final sample included 9,564 extremely obese adults (100 pounds overweight) and 304,001 healthy-weight adults, making it the largest-ever study of its kind. To eliminate other factors that could contribute to the subjects’ poor health, the study excluded people with a history of smoking and chronic disease.
The results found that obese individuals (30 pounds overweight) have a death rate 2.5 times that of people with a healthy weight. That translates to a loss of 6.5 to 13.7 years of life.
For those with extreme obesity, this statistic is even more shocking. In fact, extreme obesity shortens life expectancy even more than smoking, the study found. Healthy-weight smokers lost an average of 8.9 years of life while extremely obese persons lost 9.8.
Extreme obesity is on the rise in the United States. One in six American adults is now extremely obese, a number that has more than quadrupled in the last 30 years. An additional one-third of adults are obese and over two-thirds are overweight.
What caused this obesity epidemic in the first place?
According to a new study by Stanford University School of Medicine researchers, the culprit is under-exercise, not overeating.
The study analyzed survey results from 23,930 participants between 1988 and 2010, and found that the number of Americans that don’t exercise has increased significantly while daily caloric intake has remained stable.
The percentage of women reporting they never exercised increased from 19 percent to 52 percent between 1988 and 2010. The percentage of inactive men increased from 11 percent to 43 percent over the same time period.
Corresponding with this decrease in physical activity, obesity rates rose from 25 to 35 percent in women and from 20 to 35 percent in men over the time span.
The researchers found no significant change in calorie, fat and carbohydrate consumption.
While the Stanford study revealed a clear correlation between obesity and exercise rates, the authors noted that while a causal relationship is assumed, it has not been proven. It is unclear whether the individual’s obesity leads to decreased exercise or if it’s the other way around.
Losing weight is proven to significantly reverse the health effects of obesity. While weight loss requires a combination of diet and exercise, this new research suggests that for the severely obese, exercise is a good first step.