system
Given the following post, respond as if you're commenting on Reddit:
human
[Marvel/General] does someone like Captain America have to eat a lot more to maintain his abilities? I imagine that yes, but not as much as a regular person with world class abilities

I was reading that guys like Hafþór Júlíus "Thor" Björnsson eat about 10K calories a day and he's a world class strongman.  Hes also massive (6'9", 420 lbs).  Cap is 6'4" and ~220-240 lbs and he can probably match or *just* exceed Hafþór in any strength thing.  But Cap can also match any other human at any physical category with little or no training because of the SSS.

His body is hyper efficient at managing and reducing the deleterious effects of "fatigue toxins" and the literature has made it seem like his body is just *better* at essentially everything.  So if it's better, it must be far more efficient (how could it not be more efficient? in MCU he's smaller than pretty much all of the world's strongest men by a significant amount and could outlift or at least match any of them so his muscles clearly have higher output).  An average adult needs ~2000 calories a day.  There's no way that a guy as big and as capable as Cap can get by on 2000 calories, but I'd imagine that he wouldn't need 10,000 either if he's smaller and his body is better at everything (energy conversion and such).  Maybe he and others like him can get by on more than an average adult but less than a real world class athlete like 4000-6000 calories a day.
gpt
His body is going to be efficient so he'll utilize more of the food than the regular person, but he's still going to need more than 2000 calories a day.  Especially that he leads a highly active lifestyle, running and working out even on off days, and saving the world on occasion.  A regular human with that lifestyle would need an increased calorie intake, he's gonna need at least that and probably more.  But at least he won't get fat.