(CNN)Our
favorite fast foods could come back to bite us, according to a report
released Wednesday -- and it's not just the extra calories.
The new report grades the 25 largest US fast food chains on where they stand on antibiotics.
The results are a mixed bag: For the third year in a row, the only two As were awarded to Chipotle Mexican Grill and Panera Bread. More companies passed this year than ever before.
But
11 of the top 25 chains received an F, having taken "no (discernible)
action to reduce use of antibiotics in their supply chains."
Nine companies didn't respond to the survey at all, just like last year.
"These
drugs have historically been given to animals that are not sick, to
accelerate weight gain and prevent disease in crowded and unsanitary
industrial farming conditions," wrote the authors, who come from six
public interest groups including the Natural Resources Defense Council, Consumers Union and the Center for Food Safety.
