By Valerie Robitaille
NOTE: This article was written several years ago and since then scientists have been questioning the validity of the estimated “millions and billions” of years humans and the Earth have been around. Nonetheless, the paleo diet is still a valid, healthy way of life.
The nutritional needs of today’s humans arose through an evolutionary process that is at least 2 million years old. For most of this 
time, and certainly during the Paleolithic era, humans were hunter/gatherers; eating only wild game, uncultivated vegetables (including tiny amounts of grain) and the occasional fruit.
Approximately 11,000 years ago agriculture appeared on the scene and humans began cultivating grains for their food. Less than 2 centuries ago the Industrial Revolution began, and we have seen an increase in grain foods vastly different from the quality and quantity that our ancestors ate. Ten thousand years, and certainly 200 years, is just not enough time (on the geologic/evolutionary scale) for the human body to adjust to this change in food types. This is especially true for the refined grains typically selected from the supermarkets of today’s industrialized nations (cereal, pasta, bread and anything made with grain flour).
Skeletal remains show that our Paleolithic ancestors typically developed lean body mass in considerable excess of that common among us today. This is certainly no surprise as the demands of life of a hunter/gatherer society are strenuous. The demands of the agricultural period were also strenuous, but it took the Industrial Revolution to create a situation where productivity and human caloric expenditure did not equal out, and people began getting modern day diseases.
Pre-agricultural humans were unavoidably physical, and required a caloric intake greater than that of most 21st century Westerners. The game and wild plant foods they ate contained less fat, more protein, more roughage, and more micronutrients (vitamins & minerals) than do foods commonly eaten today (and zero hormones, antibiotics, and all the extra substances that are fed to feed lot animals). Some fruit, roots, legumes, nuts and other non-cereals provided 65-70% of the average forager’s daily diet. These foods were generally consumed within hours of being gathered with minimal or no processing, and often uncooked.
The typical carbohydrate intake of our ancestors constituted 45-50% of daily energy, much like current affluent countries, but there was a marked qualitative difference – very little was from cereal grains, and absolutely none was from refined flours. Only 23% of American carbohydrate consumption is derived from fruit or vegetable sources, and for Europeans the proportion is lower still.
Pre-agricultural humans consumed roughly three times the vegetables and fruit that typical Westerners today do, and much current carbohydrate intake is in the form of sugars and sweeteners. Such products, together with foods made from highly refined grain flours provide ‘empty calories’ (food energy without essential amino acids, essential fatty acids, micronutrients and phytochemicals). Energy sources of this type were much less available to hunter-gatherers; they were fond of wild honey, but as a seasonable delicacy, and it was not always accessible even then.
Not only are sugars and highly refined flour products devoid of nutrients other than those that create energy for us, they are also low in bulk, so they can be eaten quickly and occupy only a small proportion of the stomach. The bulky carbohydrate sources that fueled human evolution had to be eaten more slowly and usually produced more gastric distention. This stimulates neurotransmitters in the brain that tell the body it is full.
So even though we have made huge leaps in so many areas as an advanced civilization, it is no mystery that we will go down in history as the era plagued with degenerative diseases seen only in the most affluent countries. Be informed.
P.S. I am so very sorry if my vegetarian/vegan readers take offense to this article but it may be a lifesaver for someone else.