In a nutshell, Paleo is a way of eating that is based on the foods that would have been eaten during the Paleolithic era which dates from approximately 2.5 million to 10,000 years ago.
The Paleo diet was limited to foods that could be obtained by hunting and gathering which were mainly lean meats, fish, fruit, vegetables, nuts and seeds. The human body evolved over the years to adapt to the use of these foods as fuel and thrive