The Safest Room - Lateral Thinking

A murderer is condemned to death. He has to choose between three rooms. The first is full of raging fires, the second is full of assassins with loaded guns, and the third is full of lions that haven't eaten in 3 years.

Which room is safest for him?

The Safest Room

Which one;find it here! 

Source 

The Safest Room - Lateral Thought

What was the puzzle?

If murderer has a little brain then he would choose the third room 

straightaway. How lions can stay alive for 3 years without eating anything?