there's ways to do it so it isn't just a decreasing bar

Think about Valheim's food system. If you aren't familiar, if you have no food you have 25 health only and 50 stamina (i think)? You have 3 food "slots" and food has various durations from 10 minutes to an hour. Various foods give various buffs, focusing on health, eitr (mana), stamina or balanced food. Your food load-out can be customized for whatever you need (more stam for building/exploring, more health for boss fights, etc). Unlocking new higher tier foods makes you more powerful in a direct way, and you use lower tier plentiful foods when you're doing low risk stuff like hanging around your base.

That's a "positive" system instead of the "negative" system of just needing food or you don't heal/die - and it's way more fun, interact-able and interesting.