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

Saturation is measured in units of nutrition. There are 2 distinct measures of saturation.

Maximum nutrition, or how much nutrition a pawn can store at any one time. Adult humans can hold 1.0 nutrition. For them, 1.0 nutrition is 100% saturation. This property is almost entirely controlled by body size 1.0 * body_size.
Human teenagers (ages 13 - 17) are a special exception; they are smaller than adults, but have a special multiplier to maximum nutrition so that have the same amount of max nutrition.
Hunger Rate, or how much nutrition a pawn loses per day. Adult baseline humans hunger at a rate of 1.6 nutrition per day. This is determined by species and a variety of other factors.

In general, humans hunger more than similar animals. An alpaca has the same body size as a human, but only hungers at a rate of 0.44 nutrition per day. A megasloth is four times larger than a human, but hungers at the same rate. Generally, carnivorous animals hunger slower than omnivores and herbivores - a coguar eats less than half the food of a husky, for instance.

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)	×100%
Hungry	12.5% to 25%	-6	×50%
Ravenously Hungry	>0% to 12.5%	-12	×25%
Malnourished	0%	-20	×0%

Once a pawn reaches 0% saturation, they will start becoming malnourished. Malnutrition is an ailment and has an entirely separate progression to hunger rate. Malnutrition severity rises by 2% every hour, and once it reaches 100%, the pawn will die.

Speed of animals' production (wool, milk, eggs or chemfuel) is also dependent on the saturation level (see Levels of Saturation below). Production is 1/2 when the animal becomes hungry, reduced to 1/4th 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.

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	Threshold range	Change per hour	Change per day	Game time in state^[1]	Game time since 100% food^[2]
Fed	100% - 25%	-6.67%	-160%	11.25 hours	0 hours
Hungry	25% - 12.5%	-3.33%	-80%	3.75 hours	11.25 hours
Ravenously Hungry	25% - >0%	-1.67%	-40%	7.5 hours	15 hours
Malnourished	0%	N/A ^[3]	N/A	50 hours	22.5 hours

↑ Game time spent in the state from 100% before crossing the lower threshold, assuming no rest is gained
↑ Game time spent before entering the state, assuming no rest is gained and the starting saturation is 100%
↑ Malnourished does not impact saturation directly. Rather, it increases the "Malnutrition" ailment by 2% per hour, and when this reaches 100%, a pawn dies. This ailment will increase hunger rate of a pawn, but only when they have access to food again.

Hunger Rate Modifiers

The following factors will modify hunger rate:

Hunger rate factor

All hunger rate factor modifiers stack additively. Once added up, they stack multiplicatively with other modifiers to hunger.

Gourmand trait - +50% hunger rate
Stoned on smokeleaf - +30% hunger rate
Go-juice withdrawal - +50% hunger rate
Malnutrition -
- Trivial: +50% hunger rate
- Minor: +60% hunger rate
- Moderate: +60% hunger rate
- Severe: +60% hunger rate
Hunger pangs persona trait - +50% hunger rate
Neural supercharger - +20% hunger rate
Biostarvation (outside of vat) - +50% hunger rate

Other multipliers

All of these modifiers stack multiplicatively with each other and with the hunger rate factor listed above.

Gut worms - ×200% hunger rate
Reprocessor stomach - ×75% hunger rate
Nuclear stomach - ×25% hunger rate
Genetic metabolic efficiency - Positive metabolic efficiency reduces hunger by −10% per point. Negative metabolic efficiency increases hunger by +25% per point. Positive and negative metabolic efficiencies are added/subtracted from each other. Metabolic efficiency is effectively capped at -5 and +5. The final metabolic efficiency is used to determine hunger rate, and will stack multiplicatively with other hunger rate modifiers.

Despite its name and description, the Metabolism stat has no impact on hunger rate.

Overeating

Pawns will attempt to eat as their next action once their saturation level reaches 30% to avoid being hungry. Pawns make no effort to avoid "overeating", so 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 (0.30 saturation) will go to 1.0 saturation and waste up to 0.20 nutrition of food (22% of the meal). In practice, the process of eating takes some time, so not all the food is wasted.

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 smaller sized animals. These foods provide more nutrition than raw food, but won't be overeaten like a regular meal would.

Malnutrition

Main article: 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.

Status levels

Needs: Beauty • Chemical • Comfort • Drug addiction • Food • Indoors • Outdoors • Recreation • Rest • Deathrest • Energy • Kill satiety • Learning • Play
Related: Hemogen
Other: Mood (Mental break • Mental inspiration)

[1] Game time spent in the state from 100% before crossing the lower threshold, assuming no rest is gained

[2] Game time spent before entering the state, assuming no rest is gained and the starting saturation is 100%

[3] Malnourished does not impact saturation directly. Rather, it increases the "Malnutrition" ailment by 2% per hour, and when this reaches 100%, a pawn dies. This ailment will increase hunger rate of a pawn, but only when they have access to food again.

[1]

[2]

[3]