As I continued researching this phenomenon, I became aware of the related work of Dr. Daniel Lieberman, of Harvard provides key insights as to why humans, especially adolescent and young adult females, have such a compelling attraction to food. He describes how humans went through a series of crucial changes over the last two million years, which centered on reproduction and food.
The life story of one of our female Paleolithic ancestors was one of a constant searches through a hunting and gathering lifestyle for an adequate amount of food for her own bodily needs, for conceiving and carrying a baby to term, and for three years of breastfeeding. A 110-pound woman would require about 1800 calories per day for just her own needs. When she became pregnant or was breastfeeding,she would have needed an extra 500 calories per day. This situation, by the way, would have constituted her lifestyle for most of her adult life. Our Paleolithic ancestors’ biggest challenge was obtaining their daily food by hunting and gathering outside of the tropical jungle environment they had formerly occupied. It required around four miles of walking per day and much laborious gathering to find and often times dig out the foods that were buried underground in the form of tubers. Other dining possibilities were nuts that came in hard shells. There were also berries and roots that were often accompanied by toxins. Essentially, there was a price to pay for all of those food sources, usually in the form of physical effort.In these new, open environments with low densities of seasonal, edible plants, the first hunter-gatherers would have had to forage for a large variety of plants.
As alluded to earlier, this was oftentimes a very challenging task because of large boulders that might need to be moved, the effort of digging plants up, etc. to get to them. This could take up to twenty minutes of hard labor for each food item obtained. Then, once they were in hand, they had to be pounded or cooked in order to soften the indigestible fiber.That scenario presented a great challenge, especially to reproductive-age females.
Our female Paleolithic ancestor would have probably conceived at about 18 years old and had her first baby at 19 years old. At that time, she would have required the extra 500 calories per day. As the pregnancy went on, she would have become less able to gather an adequate amount of food while still needing the extra calories. Then three years later, she would have become pregnant with child number two. After giving birth, she would be encumbered in her gathering by a toddler as well as the demands of breastfeeding.
Anthropologist Dr. Helen Fisher says that women were responsible for bringing home 60-80 percent of the daily food procurement through their gathering while human were on the African plains. I would guess that this was probably largely accomplished by the pre-reproductive-age girls and the post-menopausal women who would have not faced the childcare challenges the reproductive-age women did. This childbirth and child-rearing process would have repeated itself and continued until a woman reached menopause.
For each of her older children who had been weaned but were not yet able to forage for themselves, she would have needed about 1,000 to 2,000 additional calories per day. Survival Through Division of Labor Faced with this situation, it is clear that many of our ancestral grandmothers and their children must have gone hungry and been on the verge of starvation much of the time.
This brings us to a key point in our understanding of SEX IQ and sexual empathy. An additional source of food was necessary for reproductive age women and, in order to accomplish this crucial provisioning that was so important to the development of our species, there had to be cooperation between the sexes. It appears that meat, which is a rich source of calories, fat, salt, zinc, and iron, became part of the human menu about two and a half million years ago.
Males, because they were not encumbered by toddlers and didn’t have to breastfeed, became the hunters while females gathered plants. This division of labor was a key factor in human success and exceptionalism. Dr. Lieberman writes, “Male chimps rarely if ever share food, and they never share food with their offspring. Hunter-gatherers, however, marry each other and husbands invest heavily in their wives and offspring by provisioning them with food. A male hunter today [from traditional foraging societies in the 21st century] can acquire between 3,000 and 6,000 calories a day—more than enough food to supply his own needs and provision his family... Fathers in turn, frequently depend on plants their mates gather, especially when they come home from a long hunt, hungry and empty-handed.”