Saturation

Saturation is the game mechanic that controls Characters' needs for Food, and is directly tied to Eating, the game mechanic which fills that need. A character with a higher saturation value has eaten recently, and is more full than another character with a low saturation level. You can view saturation of all humans and tamed animals by viewing the "Food" bar and the corresponding mouseover text in the Needs tab.

General mechanics

The actual value of saturation is the amount of usable nutrition inside a pawn and decreases with time. When a pawn eats, the nutritional value of the food is added to the saturation value of the pawn, but is capped by the maximal saturation value, which is coincident with the creatures body size. Similarly, the saturation can't go below 0, and the creature instead starts becoming Malnourished.

Speed of animals' production (wool, milk, eggs or chemfuel) is dependent on the saturation level (see Levels of Saturation below). Production is halved when the animal becomes hungry, reduced to one quarter of the normal rate when ravenously hungry, and completely stopped when in the malnourished level. Note that that is at 0% saturation, not suffering from the ailment called Malnutrition.

Levels of Saturation

Characters' saturation level is grouped into four thresholds: Fed, Hungry, Ravenously Hungry, and Malnourished. Each threshold exhibits different effects on a character, especially their Thoughts. The saturation level boundaries are indicated by small notches on the "Food" bar in the tab of eating pawns.

Label	Saturation	Mood modifier (Humans)	Production Rate (Animals)
Fed	Greater than 25%	(none)	x100%
Hungry	12.5% to 25%	-6	x50%
Ravenously Hungry	>0% to 12.5%	-12	x33%
Malnourished	0%	-20	x0%

Saturation Changes

Saturation goes down every tick (1/2500 of a game hour) depending on the character's current saturation and modifiers on their hunger rate.

The following table describes saturation changes of a common human (100% hunger rate, 1.0 max nutrition)

Saturation	Change per hour	Change per day
Fed	-6.67%	-160%
Hungry	-3.33%	-80%
Ravenously Hungry	-1.67%	-40%

Rounding Error and Eating Thresholds

Pawns will attempt to eat as their next action once their saturation level is in the hungry state or lower. Pawns make no effort to avoid "overeating", and any excess nutrition in the food is lost. A default pawn that eats a simple meal (0.9 nutrition) as soon as it is hungry (0.25 saturation) will go to 1.0 saturation and waste .15 nutrition worth of food.

This effect is stronger in animals with lower body sizes - a Labrador retriever with 0.75 body size will get hungry at .1875 saturation and waste .3375 nutrition from the same simple meal. Smaller, more fungible food sources like berries or haygrass (0.05 nutrition) have less of this waste, as the waste will never exceed a single item's worth of nutrition. This makes kibble and pemmican particularly useful as feed for animals with smaller body sizes, as they are small food sources that benefit from the increased nutrition due to cooking.

Malnutrition

When the saturation reaches 0, pawns will become malnourished at a pace of 2% malnutrition per hour.

Note, that in extreme situations, when death from malnutrition is a primary concern, it might be advisable to not only keep in the ravenously hungry state to benefit from the reduced hunger rate, but to even become somewhat malnourished.

Consider for example a human at 0% saturation and 0% malnourishment with 0.9 nutrition available (one simple meal). It takes a typical human 15 hours to deplete one unit of nutrition when in the fed state. If eaten immediately, such human survives:

Hours survived	State
9.75	Fed
3.75	Hungry
7.50	Ravenously hungry
50	Starving until death from malnourishment

Giving a total of 71 hours alive.

If we instead let the human remain malnourished for 13.75 hours, before eating, the pawn survives:

Hours survived	State
13.75	Starving up to 27.5% malnourishment (minor)
3.75	Fed state with 27.5–20% malnourishment (minor)
2.50	Fed state with 20–15% malnourishment (trivial)
2.50	Hungry state with 15–10% malnourishment (trivial)
5.00	Ravenously hungry state with 10–0% malnourishment (trivial)
50	Starving until death from malnourishment

Giving a total of 77.5 hours alive.