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)?
The food meter becomes relevant only when it becomes red and you begin to starve.
You won't restore HP or energy when resting, until you find some food to fill your food bar.
Healing is only a temporary solution, but it helps you gain time.
Other than that, no penalties.
EDIT: I don't know if this has been changed recently, but in the current version a starving character has his Attack Power halved(rounded up). This changes the strategies, since this way the hungry PC becomes almost useless, making a food reserve a necessity.
As the tooltip on the food bar indicates:
Yellow bar means your character is hungry. There are no penalties at this stage. This is the best time to eat food so you don't waste any (different food items restore the food bar by different amounts, but any over the maximum goes to waste).
Red bar means your character is starving and won't regenerate.
Food is consumed by actions (moving, casting spells, swinging weapons, levers, etc.) and during resting.
When character is starving he does not lose health or energy because he is starving.
But if he is damaged or has used some energy, health or energy won't auto regenerate. No other penalties.
I had my character rest and walk with completely empty food bar and he stayed at full health. I'm playing version 1.1.3. Don't know if it is different on some different version.
You can still use potions or restoration stones to restore his h/e.
