Humans are resourceful, its disgusting to think about it when you have lots to eat, but when it comes down to it. There are many documented cases of cannibalism.
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During the Siege of Leningrad, reports of cannibalism began to appear in the winter of 1941–1942, after all birds, rats and pets were eaten by survivors.
In February 1943, roughly 100,000 German soldiers were taken prisoner of war (POW). Almost all of them were sent to POW camps in Siberia or Central Asia where, due to being chronically underfed by their Soviet captors, many resorted to cannibalism. Fewer than 5,000 of the prisoners taken at Stalingrad survived captivity. Many died early in their captivity, but cannibalism was reported.
Documented Japanese soldiers' acts of cannibalism among their own troops, on enemy dead, and on Allied prisoners of war.
In some cases, flesh was cut from living people. An Indian POW, Lance Naik Hatam Ali (later a citizen of Pakistan), testified that in New Guinea: "the Japanese started selecting prisoners and every day one prisoner was taken out and killed and eaten by the soldiers. I personally saw this happen and about 100 prisoners were eaten at this place by the Japanese. The remainder of us were taken to another spot 50 miles [80 km] away where 10 prisoners died of sickness. At this place, the Japanese again started selecting prisoners to eat. Those selected were taken to a hut where their flesh was cut from their bodies while they were alive and they were thrown into a ditch where they later died.
Another well-documented case occurred in Chichijima in February 1945, when Japanese soldiers killed and consumed five American airmen. This case was investigated in 1947 in a war crimes trial, and of 30 Japanese soldiers prosecuted, five (Maj. Matoba, Gen. Tachibana, Adm. Mori, Capt. Yoshii, and Dr. Teraki) were found guilty and hanged.
The Aghoris of northern India are a splinter sect of Hinduism who practice cannibalism in which they consume the flesh of the dead floated in the Ganges in pursuit of immortality and supernatural powers. Members of the Aghori drink from human skulls and practice cannibalism in the belief that eating human flesh confers spiritual and physical benefits, such as prevention of aging.
The list goes on and on.