Here’s some food for thought. How many calories would you get from consuming one whole human body? More than 125,000, according to a new study on human cannibalism that will either make you queasy or have you reaching for some fava beans and a nice chianti.
For more than a decade James Cole, an archaeologist from the University of Brighton in England, pondered that question while studying “nutritional human cannibalism” during the Paleolithic, which lasted from about 2.5 million years ago to about 10,000 years ago.
“I was interested in how nutritious are we actually?” Dr. Cole said. “Whenever I talk about the topic, I always get a slight sort of side view from my colleagues.”
His morbid fascination led him to create what is essentially a calorie counting guide for cannibals, which he published Thursday in the journal Scientific Reports. He is the sole author.
Dr. Cole studies early relatives of modern humans, and he is particularly interested in how ancient hominins behaved and the complexities of their lives. Paleolithic cannibalism offers a way to study that complexity, he said. If ancient hominins were similar to modern humans, they may have practiced cannibalism for a variety of reasons, including ritual, cultural, social and nutritional.
“If we have this variety in our species, I was interested to see if that variety existed in other hominins,” he said.
Calories From Cannibalism
A researcher studying cannibalism in the Paleolithic era estimated that a human body would provide an average of 125,000 to 144,000 calories, if consumed. Below, average calorie counts for some body parts.
There are several ancient sites in Western Europe where archaeologists have found evidence of early hominins that ate their own kind, like Gough’s Cave in England and El Sidrón in Spain. Generally when archaeologists study Paleolithic human cannibalism they categorize it as having either ritual meaning — for instance, for burial — or a nutritional purpose. The rough definition for nutritional cannibalism, according to Dr. Cole, was any form of cannibalism where there was no evidence that it was done for a spiritual or ritual purpose.
To test whether cannibalism was done purely for the purposes of survival, Dr. Cole wanted to investigate whether human meat even offered a nutritional meal for ancient hominins compared with other animals that they could have hunted at the time. “If we’re calling it ‘nutritional’ and we have no idea of the nutritional value, then how can that label be used?” he said.
Dr. Cole found that human thighs come in at a beefy 13,350 calories, while the calves are about 4,490 calories. The upper arms are around 7,450 calories, and the forearms about 1,660 calories. Within the chest cavity beats a heart that is about 650 calories. There are also the lungs, which come in around 1,600 calories, and below them the liver sits at around 2,570 calories. The kidneys total about 380 calories together.
He concludes that humans are not really worth eating purely for nutritional reasons. One human body could have provided a group of 25 adult males with enough calories to survive for only about half a day, he found. In contrast, such a tribe during Paleolithic times could have feasted on a mammoth, which with 3.6 million calories would have provided enough sustenance for 60 days. Even a steppe bison would offer 612,000 calories, enough for 10 days of nourishment.
He said that because humans offered such a comparatively low amount of calories, his findings suggested that some examples of Paleolithic cannibalism that had been interpreted as “nutritional” may have occurred for social or cultural reasons.
Dr. Cole is clear about his paper’s shortcomings, and there are several. First, the sample size is very small. The human calorie calculations were based off cadavers from only four adult males, so there were not any specific insights into women or younger people. Dr. Cole said the papers, which were all from the 1940s and ’50s, were the only studies he found that used the same format to share full body composition data as percentages for body weight, fat and protein content. Using those percentages, he was able to calculate the calories for each body part.
Some nutritionists were critical of this approach.
“The energy contents of lean tissue, fat and body carbohydrate are well established, and using four cadavers to get to estimates of quantities is a terrible way to go about calculating the human body,” said Susan Roberts, a nutrition scientist at the USDA Human Nutrition Research Center on Aging at Tufts University.
But other nutritionists felt the paper’s methods and calculations were valid.
David Levitsky, a nutrition scientist at Cornell University, said the way the paper calculated the caloric value of the human body was precisely the same method researchers used to determine the energetic value of beef or other animals that people consumed.
“The human calorie charts, as gross as they are, are about the best approximation to the true energetic value of the human body we can obtain,” he said in an email.
Another limitation is that the nutritional values apply for modern humans but would be on the lower end of the scale for their bulkier relatives, like the Neanderthals.
Silvia Bello, an anthropologist from the Natural History Museum in London who has also studied ancient cannibalism, agrees with the paper that Paleolithic cannibalism was probably practiced more as a choice than as a necessity. However, she said finding the motivation behind those choices would be difficult.
Dr. Cole said that despite the caveats in his study, he thought his calculations offered a good proxy for the caloric value of human meat. When asked whether he thought his friends and colleagues would show up to his next dinner party after reading about his latest paper, Dr. Cole said yes. But he added that he’d most likely just serve vegetables.