system
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human
[Halo] Has the Master Chief ever eaten anything in between Halo 2 and Halo 4?

Reason why I left out Combat Evolved is because after the game, the novel First Strike takes over.

Right after the first cutscene in Halo 2, when the Chief is in the Cairo station, the Chief automatically jumps into action. He's plunged into fighting throughout many locations, Africa, the Halo installation, High Charity, and back to Earth in Halo 3. Even then he's thrown into more locations on Africa and eventually when he's back on another Forerunner there seems like no eating break has occurred. Even on human ships it seems like he's just on stand by. 

When he awakens in Halo 4, it has been several years. I'm positive he could have had a chance when he runs into the UNSC Infinity, but what we've seen was him squabbling with Del Rio. By the time the events of the Escalations series he probably had something to eat but even then he seems to have jumped back into action.

I know his augmentation helps with quenching and controlling basic human urges, like sleep, sexual drives, etc., but for a man his physical stature, you need a lot of calories to maintain his metallic skeletal structure and muscle density. Plus, he's always moving and fighting other organisms beyond his physical strength, he must use a lot of energy. I also doubt he has much body fat to burn off as emergency energy reserves. So how does the Chief do it?

ninja edit: what about water? and how much does he sweat?
gpt
Yes, he has eaten, but we just never see it. He probably finds time to eat in the few bits of downtime that he gets; en-route to a location on a ship or Pelican, any extended time when he is waiting for something to happen or come to him, etc...

Also, what he is eating is probably some sort of energy-rich superfood like Lembas bread from LotR. It probably takes him only a few minutes to eat something that can provide the necessary nutrients and calories he needs for an extended period, possibly more than a day. So even during that downtime, there is only a small window that one might actually see him eating something. 

As for water, he probably has some sort of suit-internal reservoir that can last him a bit, but it is probably a similar situation to the food question.