That chicken sandwich you bought for a quick lunch might not be all chicken.
Researchers in Canada tested the DNA of grilled chicken from five different fast-food restaurants: McDonald's, Wendy's, A&W, Tim Hortons and Subway.
None of the samples tested were made of 100 percent chicken DNA. But it's important to note once chicken is seasoned and processed, it's not expected to hit that perfect percentage.
Most hovered around the mid-80s, which is apparently pretty standard percentage for fast food. But one sample came back with slightly troubling results. Subway strips had only about 50 percent chicken DNA.
SEE MORE: Debunking 'Halal Hysteria' Meat Myths
So what makes up the "chicken" if it's not chicken? In most cases, soy fills out the meat.
And soy products aren't always great for humans. Unfermented soy, which hasn't been confirmed to be in meats in this study, has been linked to digestive, thyroid and hormone imbalances and other serious problems.
Soy is cheaper than meat, which could be why it's in so many food products.
Subway Canada said it can't verify the study's results but claimed its chicken shouldn't be over 1 percent soy. The company said it will look into its supplier's meat quality standards.
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