What was the point of Lexie eating all the time during the most recent Grey's Anatomy episode?

The actress such is playing lexi is actually pregnant in real life, and unsatisfied on the fact that the scribt reader didnt write that into the impression she enjoy to have some reason for gaining weight for the character. the way they frisk it off was such she ate as a result of stress and the ply weapons between impression also derek triggered that. At the end of the episode when lexi and mer saw the guys were friends again mer told lexi that she could stop eating now.....