Shadow of Chernobyl Edit
In Shadow of Chernobyl, they are used to remedy the hunger condition and replenish some health.
Clear Sky Edit
In Clear Sky, which abandoned hunger, they have little real use other than healing a bit of health. They are arguably most useful as a source of cash, since most barmen will buy them at full price.
Call of Pripyat Edit
In Call of Pripyat, the hunger condition was reinstituted, though now it affects stamina restoration.