Question What do the images on the HUD mean?

The 'sad face' is to show how sick you are and as long as there is no circle around it that means you are not sick. At the moment only bumping into the bee-hive increases how sick you are. You get better by just time passing.
The glass shows how drunk you are - no circle means sober!

For eating & drinking, you need to eat approximately every 55-60 minutes (any time after the circle goes orange) by which time you should have received nearly two 'kerchings' for Quintonia points!

Many food items you can cook in the café actually have 4 'portions' i.e. you only eat 25% each time, so one batch of cooking should last one person about 3-4 hours.

If the rings turn red the generation of points reverses and you might start fainting!

The clock face shows how long left of either day or night for the region you are in.