One of South Korea's hardest-to-explain phenomena in recent months is the boom of "mokbang": Internet-streamed shows where hosts eat often supersized meals – for the audience's pleasure.

Choi Ji-hwan, a top mokbang host, told The Wall Street Journal in a recent interview that one of his satisfied viewers was on a diet seeking a vicarious thrill. Others were living alone and enjoyed his virtual company as they ate "together."

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