That is not entirely true. The anthropological and archaeological evidence shows that humans have been omnivores since they first existed, the exceptions being cultures such as the Inuit that live in areas where plants are scarce, but even they eat some plants.
Note that it is true that once humans (really pre-humans) started eating more meat, they were able to extend their range as meat is a denser source of nutrients, but humans are still omnivores rather than obligate carnivores.
There isn’t much else unless we start a revolution.