Why did you bring up Batman?
First it was Harvey Dent (Nolanverse, NON-CANON Version) who said that.
Second, in the comic book series Batman: The Cult Bruce was drugged and kept in the sewers a long time. When he finally gets out during daylight, they let him out at a park where a young couple were having a picnic. He roars and scares them away and then started eating all their food because he hadn't eaten in days. Even Bruce was broken down to the point of just acting on instinct to survive and we're talking about a man here who has great control over his pain and hunger thresholds...
I found the actual pics:
http://3.bp.blogspot.com/-A2bP-e3g2Co/U_LI--WJBFI/AAAAAAAAslg/RhUSK6BYhLE/s1600/batman%2Bis%2Byogi%2B1.jpg
http://2.bp.blogspot.com/-hoM8LD6o6Aw/U_LA0MXJB8I/AAAAAAAAsko/yubweWPB17o/s1600/batman%2Byogi%2B2.jpg