Doesn't check all the boxes, but Metal Gear Solid 3: Snake Eater hits a lot of notes, most notably in the boss fight department.

3rd person, Cold War spy, stealth, action game

• A hunger mechanic that effected performance (stamina and at around 50% would affect aim or have stomach growls that would alert enemies) and could get food via hunting, trapping or stealing and in a few situations could be used offensively

• Camo system

• Majority of the bosses that you could defeat lethally or no lethally

• Medical system was pretty nifty, not fully realistic doing first aid during battle, but had the spirit of battle injury management

• Can get a lot of lore tidbits here and there by being stealthy and eavesdropping either being nearby or using a longe range listening device and by communicating with your operational support

And there is probably other systems I am forgetting ( played it on a ps2 many moons ago). Seems there is a pc version but appears to be a port and with a controller requirement, but otherwise I thought it was a loaded game for its time ( released 2004)