Watch out, chicken nugget fans: Researchers in Mississippi recently ran a study to see what those mysterious nuggets really consist of, and their findings are not exactly palatable.

The researchers tested chicken nuggets from two national fast food chains in Jackson, Mississippi. One nugget had less than 50% muscle tissue (what people usually think of as chicken meat), while the rest was fat, blood vessels and nerves. Upon further examination, the researchers also saw cells that line the birds’ skin and internal organs.

The second type of nugget had only 40% muscle and otherwise consisted of fat, cartilage and bone. Researchers concluded that the popular nuggets are a poor source of protein and high in fat.

The researchers have not revealed which restaurants the tested nuggets came from. Since  nuggets from only two chains were tested, however, it’s difficult to draw large conclusions about the contents of chicken nuggets in general.