The diet of Neanderthals consisted primarily of meat, based on several pieces of evidence. There is some evidence, however, that shows Neanderthals may also have consumed plant-based food as well.
Chemical analysis on the bones of Neanderthals show that these prehistoric humans ate more protein than cave bears who also lived in the same area. The theory that Neanderthals have a meat-centered diet is supported by the presence of animal bones from large prey in and within the area where Neanderthals were believed to have lived. The meat-focused diet of Neanderthals is believed by some experts to be the cause of their disappearance.
A research that was published in January of 2011 in the Proceedings of the National Academy of Sciences seemed to contradict these theories. In the research led by Smithsonian Archaeobiologist Dolores Piperno, fossilized tartar from Neanderthal teeth shows evidence that Neanderthals also subsisted on a wide variety of plants. The plant starch microfossils found in Neanderthal tartar also appeared distorted, which suggested that the plants might have even been cooked before eating.