17 Billion? How the CDC Estimated How Many Binge Drinks US Downs Each Year

Here's a number that's hard to swallow: U.S. adults consume more than 17 billion alcoholic drinks during binges each year, according to a new report.

That works out to about 470 drinks per binge drinker per year, according to the report, from the Centers for Disease Control and Prevention (CDC).

But how did the CDC calculate these numbers?

The results are based on interviews with more than 400,000 U.S. adults in all 50 states in 2015. The interviews were carried out monthly in each state, and included a representative sample of adults.

Participants were asked how many times they binge drank in the last month, and how many drinks they consumed on these occasions. Binge drinking was defined as consuming four or more drinks per occasion for women, and five or more drinks per occasion for men. [7 Ways Alcohol Affects Your Health]

Then, the researchers took these monthly binge-drinking episodes and multiplied it by 12 to get a yearly estimate. Because the interviews took place during each month of the year, the researchers were able to take into account seasonal variation in drinking, they said.

The report found that about 17 percent of U.S. adults, or 37 million people, reported binge drinking in 2015. Each binge drinker reported an estimated 53 binge-drinking episodes per year, or about once a week, and consumed an average of seven drinks per episode.

The researchers then multiplied the estimated total number of binge-drinking episodes by the largest number of drinks consumed per episode for each drinker, for a whopping 17.5 billion binge drinks consumed in 2015.

Binge drinking can result in dangerous behavior, such as drunk driving; and over time, it can increase the risk of serious health problems such as cancer, heart disease and liver failure, according to the CDC.

"This study shows that binge drinkers are consuming a huge number of drinks per year, greatly increasing their chances of harming themselves and others," study co-author Dr. Robert Brewer, the lead researcher in the CDC's alcohol program, said in a statement. "The findings also show the importance of taking a comprehensive approach to prevent binge drinking, focusing on reducing both the number of times people binge drink and the amount they drink when they binge."

Editor's note: This article was updated on March 19 at 4:15 pm ET to include a more accurate description of how the researchers calculated the total number of binge drinks.

Originally published on Live Science.