In the comics, he was once self-exiled from Earth for several weeks, and described being "lightheaded from hunger" before finding a planet with food he could eat. (This was late-80s/early 90s, not long after John Byrne's reboot; at this point his powers had been rewritten as less "all-powerful" and he required both his air mask, and a hyperspace jump belt in order to roam the stars). There have been scenes from various comics in which he is shown eating or thinking about hunger, both as Superboy and as an adult, but with nearly 7 decades of comics and other media, I don't know how to find them.

EDIT: I just thought of one. In the Kingdom Come miniseries, he eats at the "Planet Krypton" restaurant with Batman and Wonder Woman.

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