She Eats, I Gain

Protagonist, a mukbang streamer, inexplicably can't eat, feels full, and gains massive weight, becoming obese and unrecognizable. Her colleague, the antagonist, joins, goes viral as a mukbanger who never gains weight, earning millions. As protagonist's obesity worsens, she suffers multiple organ failure. She suspects all food her colleague consumes transfers to her stomach. Her attempts to persuade the antagonist to stop are fruitless, and she is ultimately stuffed to death.