Buying chicken these days is not like it used to be. With labels like "100 percent natural," "organic," "grain-fed," and "free range," many consumers don't really know what they're buying.

Federal regulators recently demanded that Tyson Foods remove "raised without antibiotics" from its chicken label. The U.S. Department of Agriculture originally approved the slogan, but later said it erred.

USDA is also taking a closer look at labels that proclaim "100 percent natural." According to USDA, those words mean the poultry doesn't contain artificial ingredients like preservatives. But, experts warn, there are no guarantees.

"100 percent natural remember, no inspections are done. So we don't know if those claims are really true," says Shannon Wallace, R.D., registered dietitian with Baylor University Medical Center at Dallas.

Chicken labeled as "organic" must meet much stricter standards. Inspections are conducted and organic chicken cannot contain artificial ingredients, hormones or antibiotics. But are those really harmful to consumers?

"The USDA does not make any claims that organically produced food is any safer or more nutritious than conventionally produced food," Wallace said.

Another popular chicken label is "grain fed." This is supposed to mean the chicken was not fed animal byproducts, but just like "100 percent natural" and "free range," there is no outside monitoring for this claim.

And probably the most confusing label of them all is "free range." Chicken labeled as "free range" is supposed to be leaner, but again, experts warn the claim can be deceiving.

"Free range does not always mean that the animal has been in an open area its whole life. It may only mean they were in a restricted area and let out into that open area one time during their life," said Wallace.

So what should you shop for in chicken?

"If you would like to have a healthy diet, trimming the fat or buying leaner cuts of meat is always important. And the research is still out regarding these other issues of hormones and antibiotics," Wallace said.