Neanderthals didn't only eat meat. Studies show they ate many kinds of plants. Plant material was found in the skeletons of Neanderthals, in which a chemical known as isotopes were detected in the teeth of the remains that were found.This showed that they ate meat and a large amount of plants. The main meat that they would eat was mammoth. This evidence is the most interesting yet to be found. The neanderthal's bones have a substance higher proportion of nitrogen-15 (¹⁵N).