My "victory" in an adventure mode playthrough was constructing a simple cabin over many days and nights, complete with a casket to bury the last of the giant spiders that I had wrangled from a strange pasture. It had all the necessities - a workshop, some barrels and storage, a roof, and a bed.
My weary hero hoped to lay down and finally have a reprieve from the road, but woke up in the same condition as every other nap in the mud she went through - hungry, thirsty, and not able to really appreciate life's comforts. This was particularly aggravating during construction, where I couldn't eat enough at one time of adventurer-control to stay full during both my labor shifts and nightly rests.
I propose that sleeping in a proper bed means that a unit's hunger and thirst timers are paused for the duration of the task (in a Fortress) or fast-forward (as an Adventurer). It would be most relevant for adventurers taking the effort to rest in tavern lodgings or build a camp, as their sleep cycle lasts for more ticks. For fortress citizens, it would just be a minor delay to the next time a citizen with a room goes for another snack. This is only for parity with the Adventure-centric mechanic, as the primary motivator for making dwarven beds is their mood.
This sleep benefit should only be for deliberate/scheduled sleep, not for hospital rest. I believe the unconsciousness from that condition is tracked separately, and administering rations to resting patients should be preserved. Creature-specific need counters (vampiric bloodthirst and dwarven withdrawal) don't need this benefit, since they aren't essential needs and are reset to zero when fulfilled.