So about this HUD and these hunger bars, I was the one recently to bring this up only to be shouted down that 'That's what the devs want and so that's the way it is.'
Or the slightly more ridiculous remark that avoids actually having a discussion under the guise of advice, yet nothing more than a 'You want it this way, no, but I want you to do it this other way, yes,' which is - mod it.
I'm very happy to see that Gazz has stood up and made the very legitimate point that having to open a bag to see if you're hungry or thirsty is immersion breaking.
I would also like to challenge Roland again while I'm here. Though I do concede Rolands point that having to eat and drink whenever increases the immersion for him, simply because, in real life you don't need to check books to know if you're hungry, Roland my old mate, my old pal, you're missing one serious point.
The human body has indications when food or water is low, the brain, stomach and the kidneys for example as well as many other processes involved in feedback regulate our systems so that we are made aware of being hungry or thirsty, full and hydrated, and this game is not real life.
Just as we don't need to be told we are hungry, the character shouldnt, and in real life this hunger and thirst is manifested in the awareness, so in game it should be in the HUD. You wouldn't need to open your diary or check a mobile app or look at your bio page to know when you're hungry, and that complements Gazz's point.
How you get this in the HUD is a different story.
I would suggest instead of lengthy linear bars, have four little icons with circular bars around them that deplete over time. Extremely minimalist, very convenient, and a nice reimplementation of what I personally think was a great Pimp addition to 7D.