Labels on Shady Brook Farm turkey say “no growth promoting antibiotics.” Progresso advertises that its soups contain chicken with “no added antibiotics,” and some Perdue labels say “no antibiotics ever.” And last week, KFC announced that it would be serving chicken raised without “medically important antibiotics” by 2018.

Some version of a “no antibiotic” label has recently become a selling point for many supermarket and restaurant brands—and for good reason. A Consumer Reports survey conducted in late 2015 found that 25 percent of food shoppers were buying no-antibiotic meat and poultry more often than they did the year before.

“Some 80 percent of all antibiotics sold in the U.S. are given to animals—not people—in their feed or water mostly to promote growth and/or prevent disease,” says Jean Halloran, director of food policy initiatives at Consumers Union, the policy and mobilization arm of Consumer Reports. "And that's a major contributor to the public health threat of antibiotic resistance, which is when the bacteria that cause infections become resistant to the effects of the drugs designed to kill them."

Consumer Reports' calculations of data from the Centers for Disease Control and Prevention show that about 20 percent of people sickened by antibiotic-resistant infections got ill from something they ate.

Although it's beneficial for consumers to have no-antibiotic choices at restaurants and supermarkets, these different claims mean very different things. In some cases, you might think that the animals were not given antibiotics at all, when in fact they were.

To help you know exactly what you’re buying, we’ve spelled out the meaning behind some of the most common claims and policies, and listed them from best to worst. 

Organic

To be labeled organic by the Department of Agriculture, meat and poultry must be raised without antibiotics, with one exception: Chickens and turkeys can be given antibiotics in the hatchery while the chick is still in the egg and on its first day of life. But if you also see a “raised without antibiotics” claim on a chicken or turkey product in addition to the USDA Organic label, it means antibiotics were not used at any point, even in the hatcheries. To carry the USDA Organic seal, meat, poultry, and egg producers undergo inspections, so the claim is verified.

Raised Without Antibiotics

This and related phrases, such as “no antibiotics ever” and “never given antibiotics,” mean no antibiotics of any kind were used in the raising of that animal. Sick animals that required antibiotics would be removed from the “no antibiotic” line and sent for processing with animals raised under conventional circumstances. You can trust this claim, but if the package also sports a USDA Process Verified seal, it means that USDA inspectors have made a visit to the farm to confirm that antibiotics were not used.

There are a number of companies that produce or serve meat raised without antibiotics. For example, Bell & Evans falls into this category, as do 95 percent of the chickens and 75 percent of the turkeys raised by Perdue. By the fall of 2017, Tyson Foods says that all of its retail chicken products will be “no antibiotic.” Progresso is using no-antibiotic chicken in all of its chicken soup varieties. Applegate Farms and Coleman Natural produce no-antibiotic poultry, beef, and pork, and almost none of the meat served at Panera Bread or Chipotle has been raised with the drugs. Subway has this policy for all of its chicken. (You can find other restaurant chains’ policies here.)  

No Medically Important Antibiotics

This means antibiotics used to treat people—such as amoxicillin, erythromycin, and tetracycline—have never been given to the animals.

KFC is pledging to fulfill this claim by the end of 2018. Taco Bell and Wendy’s have also promised to do the same for chicken sometime this year; Wendy’s says it is committed to making similar changes to pork and beef products, but it has not given a firm timeline for implementing that policy.

At McDonald's, this policy is already being implemented. It applies to the chicken it serves (but not to other meats).

The problem: This still allows for the use of antibiotics that aren't medically important, which can lead to antibiotic resistance to other drugs. “Resistance genes don’t discriminate,” says Tara C. Smith, Ph.D., associate professor of public health at Kent State University. Genes that create resistance to medically important antibiotics can tag along with what we think of as less crucial drugs, leading to similar consequences, in the long term, to using those critical ones.

And you have to read the wording of the claim carefully. Some companies’ policies—such as those of Jack in the Box, Sonic, and Starbucks—eliminate medically important antibiotics in chicken only for growth purposes but may still use them for disease prevention.

No Critically Important Antibiotics

Burger King recently announced plans to no longer serve poultry raised with “critically important” antibiotics by the end of 2017. This means the company has stopped using only some of the medically important antibiotics used to treat people.

And in the case of poultry, a "no critically important antibiotics" claim doesn't translate to meaningful change in antibiotic use, Halloran says. Consumer Reports evaluated the list of antibiotics that the World Health Organization classifies as “critically important in human medicine” and found that most of them are not typically used in chicken production anyway.

No Growth-Promoting Antibiotics

The “no growth-promoting antibiotics” label, which is found on Shady Brook Farms and Honeysuckle White turkey (both owned by Cargill), means that no antibiotics were fed to the animal to speed up growth.

According to guidelines from the Food and Drug Administration, medically important antibiotics can no longer be used for growth promotion, although drugs not used in people can be used, so this practice is only a slight improvement over the industry standard.

Still, consumers may easily misinterpret this claim. “Many people will likely think it means ‘no antibiotics’ at all,” Halloran says. “But this company is still using antibiotics for disease prevention, which the FDA also permits. To preserve antibiotic effectiveness for people, the drugs should be used only in rare instances when animals are sick.”