Why don’t we eat each other for dinner? Too few calories, says new cannibalism study

Humans may be the most dangerous game, but they're hardly the most nutritious (despite evidence of cannibalism, like these skulls found on an island in Fiji, above). A new, slightly morbid study based on the calorie counts of average humans suggests that human-eating was mostly ritualistic, not dietary, in nature among hominins including Homo erectus, H. antecessor, Neandertals, and early modern humans. To find out just how many calories an average body packs, one researcher used a pair of studies from 1945 and 1956 that analyzed the chemical compositions of four adult males whose bodies were donated to science. On average, an adult male human contains 125,822 calories of fat and protein, enough to meet the 1-day dietary requirements of more than 60 people. (The single most energy-rich part of the body? Fat, with a whopping 49,399 calories per human. The least? Teeth, at 36 calories.) The numbers represent a lower limit, as Neandertals and other extinct hominins likely had more muscle mass than modern humans. Still, when compared with other animals widely available to ancient humans like mammoths (3,600,000 calories), wooly rhinoceroses (1,260,000 calories), and aurochs (979,200 calories), it hardly seems worthwhile to hunt hominins that are just as wily and dangerous as the hunters, the researchers conclude today in Scientific Reports . Some instances of cannibalism from nine Paleolithic sites in Europe, which date from 936,000 to 14,700 years ago, might be chalked up to starvation or not wanting to waste a perfectly good body that died from natural causes. But in most cases, the study suggests, it’s more likely that prehistoric cannibalism was primarily ritualistic in nature, consecrating victory over a hopefully tasty enemy.