2nd Kings

"And there was a great famine in Samaria: and, behold(see), they besieged it, until an ass's head was sold for fourscore pieces of silver, and the fourth part of a cab of dove's dung for five pieces of silver. And as the king of Israel was passing by upon the wall, there cried a woman unto him, saying, Help, my lord, O king. And he said, If the Lord do not help thee, whence shall I help thee? out of the barnfloor, or out of the winepress? And the king said unto her, What aileth(afflicts, pains) thee? And she answered, This woman said unto me, Give thy son, that we may eat him to day, and we will eat my son to morrow. So we boiled my son, and did eat him: and I said unto her on the next day, Give thy son, that we may eat him: and she hath hid her son,"

This passage speaks of a great famine that hit Samaria, due to the lack of food it seems that cannibalism was used to stay alive. It should be noted that just because the Bible mentions something does not mean it supports it; the Bible speaks of many atrocities, but we must remember the Bible is recording history, and in history, bad things such as this can happen.