In Legend of Grimrock every character has a food meter which gradually decreases as you move, fight and rest. You find food scattered about the dungeon, both from enemies and on the floor (3 second rule clearly not an issue) to fill the meter back up.
What effect does a low food meter have? Is there a penalty to my skills or attributes? Does it cost more energy to cast spells? Is there no effect until a certain point (the manual mentions starvation but does not give any description)?