Drinking too many sugar-sweetened beverages is a key contributor to youth obesity. In order to better understand why children reach for these drinks so frequently, Brian Elbel, PhD, an associate professor in the Department of Population Health at NYU Langone, and his research team fanned out to area fast food restaurants. They collected and surveyed hundreds of patrons’ receipts.

“It’s always tough to get data on kids that represents the real world, and this was based on what kids are actually purchasing, not some experimental setting,” says Dr. Elbel, who is also director of NYU Langone’s Comprehensive Program on Obesity.

“Any information we can find about why this high-risk group of kids is purchasing these drinks is important,” Dr. Elbel tells Reuters.

He and his colleagues found children were more likely to get a sugar-sweetened beverage when they ordered a combination meal. Other predictors included if the child was male or above age 12, or if the parents had a high school degree or less.

Sugary beverages like soda, sweetened tea, and flavored milk add about 179 calories to a meal, yet federal dietary guidelines recommend that children get only 10 percent of their total daily calories, or about 120-180 calories, from sugar.

Read more from Reuters.