The Paleolithic diet was pioneered in the '70s as a way of replicating the diet of hunter-gatherer societies. More of a lifestyle than a strict regimen, those who eat paleo centre their diet on meat, fish, root vegetables, fruit and nuts. Dieters focus on rich food, avoiding grains, dairy, salt and any processed food.
Michael Bisson, associate professor of anthropology at McGill University, says the diet is close to what humans ate in Paleolithic times. "Diet is entirely contextual, in terms of the environment and technical surrounding of a particular people," said Bisson. "What they appear to be doing is replicating a diet from very late in the Paleolithic, and there's nothing wrong with that."