There may be more than meets the eye in your meat, according to a government whistleblower and an ABC News investigation.
Gerald Zirnstein, a former scientist with the U.S. Department of Agriculture, told ABC News that 70 percent of ground beef sold at supermarkets nationwide contains a substance he calls "pink slime."
Pink slime, he says, is filler that's created by combining beef waste trimmings, simmering them and then treating them with chemicals to kill bacteria. The "slime" is then mixed with ground beef.
Zirnstein tells ABC News that the substance was once only used in dog food and cooking oil.
READ MORE at ABCNews.com.