How Long Could Humans Really Survive on Just Cannibalism? The Startling Science

Oct 6, 2025
2 min read

HOME > LOVE - FANTASY > WHAT IF?

human body protein requirements — **The brutal truth about eating your own.**

This Article Is Available In

ENGLISH - GERMAN - FRENCH - ITALIAN - SPANISH

Imagine a world where humans survive only by eating each other. Sounds horrific because it is. But if you crunch the numbers, the entire human race contains about 500 trillion calories—enough to sustain a tiny population of roughly 100 people for millions of years, assuming perfect preservation. This calculation is based on minimum viable population studies originally aimed at interplanetary missions but intriguingly applies here as well. This question touches on deep issues in cannibalism survival science, revealing the biological limits of such a diet.

Nutritionally, people can survive surprisingly well on a meat-only diet, especially if they consume organ meats and bone marrow, which provide essential nutrients missing in typical muscle and fat. Research shows that survival on all-meat diets is possible under some conditions. The field of cannibalism survival science explores these nutritional boundaries, pointing to historical examples such as the US government’s wartime push to consume “variety meats” to meet animal protein shortages during World War II.

However, the biggest problem wouldn’t be nutrients—it would be contaminated food. Cooking might kill some bacteria, but diseases spread easily through human remains, and in small populations, every outbreak becomes a devastating pandemic. The chilling reality uncovered by cannibalism survival science is that disease transmission would quickly wipe out survivors.