Very likely animals foods, other than insects, had no place in the actual diet of hominids for at least the first three-fifths of this time period. When it was introduced into the diet, it was an opportunistic supplement to plant foods and was likely limited to scavenging carcasses for bone marrow and brains and possibly organ meats such as liver and kidneys. The availability of such animal-origin foods was likely only sporadic but favorable for their energy density.
An ever increasing variety of plant foods was accepted into the hominid diet, including mature leaves, stems, roots, nuts, and seeds. These were the staples of the dietary patterns of the Paleolithic Age.
The addition of meat, i.e. animal muscle tissue, to the diet probably didn’t happen in significant quantities until the advent of cooking, corresponding to the last 10% of the Paleo period. Even then, it was likely only a supplement to plant mainstays, which were also significantly expanded by the availability of heat processing. The preponderance of evidence supports the assertion that plant foods predominated in the diets of hunter-gatherers .
The quality that best characterizes the actual diet of the Paleolithic era was versatility. Energy density was still the most sought after quality from food sources. Nutritional diversity, perhaps borne of necessity, was fed by the increasing expansion of acceptable foodstuffs.
Considering today’s concept of taste, the Paleolithic diet was a “tasteless” diet but a survivable one.
Mitton K (2000) Hunter-gatherer diets – a different perspective.
American Journal of Clinical Nutrition 71: 665–7.