Want to live longer? Turns out there’s something that can cut your life span even more than smoking cigarettes, according to a new study published in the journal PLOS Medicine: Obesity.
The study, which drew data from 20 large-scale studies conducted in the United States, Australia, and Sweden, says that people who were extremely obese died up to 13.7 years earlier than those who maintained a healthy weight.
Extreme obesity, according to researchers, refers to people with a body mass index (BMI) of 40 or more.
“We found that the death rates in severely obese adults were about 2.5 times higher than in adults in the normal weight range,” says Cari Kitahara, lead researcher and research fellow at the U.S. National Cancer Institute. “Whether losing weight would improve lifespan isn’t clear. But not becoming obese in the first place will extend your life.”
The body mass index, or BMI, is a common measurement used to examine a person’s health, based on a person’s height and weight. In the past, this measurement came under fire for not considering other health factors that may skew BMI readings, such as having more muscle. However, scientists universally agree it’s a good measurement for those who are sedentary. A healthy BMI usually falls between 18.5 and 24.9–and in contrast, a severely obese BMI starts at 40.
Kitahara decided to look at the life span of those who were obese by these standards.
Looking at data that included 9,564 obese adults and 304,011 non-obese adults, she looked at when these people died and from what causes–such as cancer or old age. She then factored in their BMI to see if there was a correlation with these deaths.
As it turned out, the higher a person’s BMI rose, so too did their mortality rate. For those with a BMI of 40, for example, their life expectancy was cut by 6.5 years. Those with a BMI up to 59.9 fared the worst, with an average lifespan shortened by 13.7 years.
Those who maintained a normal weight lived longer, however.
“We have long had clear and compelling evidence that obesity is related to the major chronic diseases that plague modern societies: heart disease, cancer, stroke, diabetes, dementia and more,” says Dr. David Katz, director of the Yale University Prevention Research Center in New Haven, Conn. “We also have data to show that the death toll of obesity is rising.”
What Should You Do?
So the news is grim–the higher your BMI, the more your life expectancy falls. So what should you do?
Researchers suggest not becoming obese in the first place.
“But to a far greater extent, it [obesity] can and must be addressed with prevention, since severe obesity rarely has to happen in the first place,” says Katz.
As for ways to prevent it, you don’t need to do anything fancy–Exercising regularly, avoiding processed foods, and focusing on a diet rich in vegetables, fruits, and whole grains will help most people maintain a normal weight. For those who need to lose weight fast too, there are other healthful eating plans as well, such as the Paleo Diet.
But whatever you do, make it consistent, say health experts. After all, the best diet is the diet you can stick to.
Readers: What is your BMI?