The obesity epidemic has shown some promise of waning recently in pre-school kids. However, for young adults and older adults, it’s still very much present and killing millions of people yearly. But reports of obesity-related deaths could actually be about three times higher than previously estimated, according to a new study.

The study found that about 18 percent of deaths among white and black men ages 40 to 85 could be linked back to obesity, a rate far surpassing that of other scientists, who had estimated that about five percent of deaths were obesity-related.

“Obesity has dramatically worse consequences than some recent reports have led us to believe,” study author Dr. Ryan Masters, who conducted the research at Columbia University’s Mailman School of Public Health, said in a statement. “We expect that obesity will be responsible for an increasing share of deaths in the United States and perhaps even lead to declines in U.S. life expectancy.”

The study is different because it accounted for differences in age, birth year, sex, and race, factors that Dr. Masters says weren’t considered in past research, which “lumped together all Americans.”

Obesity-Related Deaths in Older Adults

The researchers looked 19 versions of the National Health Interview Survey, which documented participants’ health until they died between 1986 and 2006. They focused on people ages 40 to 85 in order to rule out causes of death for young people, such as accidental deaths, homicides, and congenital conditions.

They found that black women had the highest risk of dying from obesity, at 27 percent, compared to white women at 21 percent, white men at 15 percent and black men at five percent.

Could Obesity Be Taking the Credit?

Factors such as smoking, alcohol use, and lack of health insurance were left out, and obesity could be “getting credit” for deaths caused by complications to these factors, Ken Thorpe, professor of health policy at Emory University told USA Today.

“The relative death rates among black and white men don’t make sense because black males have higher obesity rates,” Thorpe told USA Today. “And obesity-related chronic conditions, such as heart disease, cancer, diabetes, and stroke, account for a similar share of the overall cause of death among black and white males.”

According to the Centers for Disease Control and Prevention (CDC), more than a third of American adults are obese. When adjusting for age, non-Hispanic blacks have the highest rates of obesity, at 49.5 percent. A higher percentage of blacks, compared to other ethnicities, also develop diabetes and die from heart disease.

The reason black men had the lowest chances, Dr. Masters says, was because other factors, such as cigarette smoking or challenging economic conditions led to premature death before they could be affected by obesity-related illnesses.

Source: Masters R, Riether E, Powers D, et al. The Impact of Obesity on US Mortality Levels: The Importance of Age and Cohort Factors in Population Estimates. The American Journal of Public Health. 2013.