Currently there is no furniture in game and these two actions would make it necessary to have beds and chairs.
Sitting - while sitting you have a buff that increases (marginally) effectiveness of all healing stuff and maybe the rate of healing itself. Eating while seated is better than eating while running. You can seat by the fire, in lean-to, on a log, but having a bench is better while comfy chair is even better. "Better" means higher bonus. Or maybe some other bonus (faster training?)
Sleeping - Another buff that builds up while you're sleeping and drains while you're not sleeping. The buff itself could be higher food effectiveness or training speed again. Bed could be proper bed, makeshift bed made of branches and grass and portable bedroll.