One of the big selling points for the PC version of Red Dead Redemption 2 is the uncapped framerate and being able to potentially experience Rockstar's Western at more than 60 fps. Players who have avoided Red Dead's various stuttering and performance issues at launch have discovered that this high performance seems to come at a cost, however, and it's a problem that Dark Souls II PC players may remember from the early days of that game.
It all comes down to the way the game reckons time passing. In Dark Souls 2, you may recall, weapons degraded over time. PC players noticed this was happening suspiciously quickly, and it turned out that the problem was that playing the game at 60 fps rather than 30 fps made the game think, for the purposes of weapon durability, that time was passing twice as fast.
As Gamespot reports, some players believe the same phenomenon is happening in Red Dead Redemption 2. Arthur Morgan runs on three "cores": health, stamina, and Dead Eye. You keep these full by resting and using consumables, making eating regular healthy meals an important part of keeping Arthur in fighting shape. They'll decay over time, so if Arthur doesn't eat for a while he'll start to lose weight and his stamina and HP regeneration will suffer.
A redditor named jimmyoneshot says he thinks Arthur's cores decay in the PC version of Red Dead similarly to how weapons degrade in Dark Souls II. He's noticed that once the weight mechanic is introduced in Chapter 2, it's been impossible to keep Arthur from becoming malnourished—an issue that he'd never had while playing on the PlayStation 4.
After testing the game at framerates as high as 160 fps and comparing his results with the same activity level and food intake at 30 fps, jimmyoneshot is pretty convinced that the game logic for core decay is tied to framerate, which means playing at 120 fps or above gives Arthur the metabolism of a shrew (which regularly eats three times its body weight in a single day).
Other players have chimed in, noting that they've found the game's day/night cycle to pass strangely quickly, and that weather systems seem to move through areas too fast. It's conceivable that these too are moving faster due to being tied to framerate.
Anecdotally, I've noticed the same issue: Arthur in my game is perpetually malnourished, but I had chalked that up to being too lazy to do much hunting and possibly having the consumption.
One possible solution, of course, is to simply lock the framerate to 30 in the graphics options menu. However, that does eliminate one of the PC version's big advantages over its console counterparts.
Rockstar has not yet officially acknowledged this issue, but it has been rolling out patches for Red Dead Redemption 2 on PC at a pretty steady clip since the game launched. Hopefully they'll work out a fix before too long.