Is there any drawback in resting?

Another negative aspect of resting is that it expends your hunger level much more quickly than playing at normal speed.

Think of it as the game increasing the play speed by a few [units], anything affected by time is affected by resting.

The only negative thing that can happen while you're resting is that monsters can attack you,of course if you find a safe place to rest (which i suggest you do) then you shouldn't have problem.

Resting can also cause some monsters in previously cleared areas to respawn, this is particularly noticeable on the lower levels like level 6: trapped.