When you head to your favorite restaurant or fast-food joint, you may be getting a lot more in your meal than you realize, a recently released report says.

A collaborative effort by six nonprofit activist organizations, the "Chain Reaction II" report grades the nation's top 25 fast-food chains on the amount of antibiotics in their food.

More than half of the restaurants graded received a failing grade in the study.

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Antibiotics fed to poultry and livestock contribute to the growing problem of antibiotic-resistant bacteria, or “superbugs,” the study’s authors said.

The goal of the report is for more companies “to adopt policies prohibiting the routine use of antibiotics in the meat and poultry they serve.”

At the top of the list are Panera and Chipotle, which “continue to lead the pack with solid ‘A’ grades for implementing comprehensive policies that restrict antibiotics use across their meat and poultry supply,” the authoring groups said in a release.

Nine restaurant chains received passing grades while the remaining 16 were given an “F” by the report.

Subway was one of the most improved in the group, going from an “F” in 2015 to a “B” in the most current report.

Dunkin’ Donuts, on the other hand, was the only chain to be downgraded to an “F” in 2016.

“Antibiotic resistant infections already cause more than 23,000 deaths and up to $55 billion in costs each year and antibiotic misuse in animal agriculture threatens to drive these numbers even higher,” said Steven Roach, Food Safety Program Director of Food Animal Concerns Trust. “Even the CDC agrees that with the recent discovery of the latest colistin-resistant superbug, the end of the road for antibiotics is not far.”

More than 70 percent of medically-important antibiotics in the United States are sold for use on livestock and poultry, the report’s authors said.

Additionally, more than 96 percent of those drugs are routinely distributed in feed or water, often to animals that are not sick, to speed up growth and help animals survive crowded and unsanitary conditions on industrial farms.

The practice of giving healthy animals antibiotics is contributing to the growing epidemic of drug-resistant infections in humans, the report said.

At least 2 million Americans are infected with antibiotic-resistant infections every year, and at least 23,000 die as a direct result, according to the Centers for Disease Control and Prevention.

The Chain Reaction II report was compiled by the Natural Resources Defense Council, Food Animal Concerns Trust, Friends of the Earth, Consumers United and the Center for Food Safety.