Paleo diet is based on ancient dietary practices which have evolved since people were hunter-gatherers until they started farming about 10 millennia ago (about 8 thousand years ago). While these practices had little nutritional value when we started farming (since we were eating plants that contained no protein), it was soon discovered that we could improve our nutritional quality by modifying these foods (and adding additional animal proteins). This resulted in many diets which are based on hunter-gatherer practices (which we now know as Paleo diet) where one has essentially limited diet during one's entire life from birth until death because it was so difficult living such an unbalanced lifestyle (despite having better nutrition compared with today). However some modern day societies have decided not follow paleo lifestyle or Paleo diet because they believe it does not meet their needs (they believe eating animal proteins provide many benefits including weight loss) .