While overall life expectancy in the U.S. is at an all-time high – a new study has found that is not the case in several regions of the country – especially in the South.

The study, done by researchers at the Institute for Health Metrics and Evaluation (IHME) at the University of Washington, looked at data between 2000 and 2007, and found that more than 80 percent of counties in the U.S. are lagging behind compared to the average of 10 nations with the best life expectancy in the world.

"We are finally able to answer the question of how the U.S. fares in comparison to its peers globally," Dr. Christopher Murray, IHME Director and one of the paper's co-authors, said in a news release. "Despite the fact that the U.S. spends more per capita than any other nation on health, eight out of every 10 counties are not keeping pace in terms of health outcomes. That's a staggering statistic."

So why are Americans shaving years off of their lives? Well, the researchers said it has a lot to do with rising obesity rates and other factors such as smoking.

For example, Mississippi has consistently been one the most obese states in the country over the last five to six years. As a result, five counties in that state have the lowest life expectancies for women, all below 74.5 years, putting them behind nations such as Honduras, El Salvador and Peru. Four of those counties, along with Humphreys County have the lowest life expectancies for men, all below 67 years, which puts them behind Brazil, Latvia and the Philippines.

The researchers said to combat this problem, something needs to be done on a community level.

"We are building the evidence for focused interventions that will make an impact locally," said Dr. Ali Mokdad, professor of global health at IHME. "If we as a society are going to fund programs to improve health, we must ensure that we are measuring the impact, because these life expectancy numbers show that what we have been doing up until now clearly is not working.”

The new study is published in the journal Population Health Metrics.