But the truth is, humans have been consuming red meat for a long, long time. In fact, scientists have identified animal bone fossils from 2.6 million years ago that showed butchery marks made by early humans. Our ancient ancestors were smart eaters: Red meat has a plethora of nutrients. A serving of red meat contains a healthy dosing of protein as well as vital nutrients including iron, vitamin B12, and zinc, among others. But it's absolutely not true that red meat is the only food that provides these nutrients. The key, says Leslie Bonci, a registered dietician and sports nutritionist, is to be aware of what you are missing and fill in the blanks. "Things like zinc, magnesium, and B vitamins are not unique to red meat, but they certainly are a major component of them," Bonci says. "If you give it up, then you are going to have to work harder and find lots of other types of food items to be able to make up that difference."