The poem reads like a portrait of an eating disorder, with the disorder itself treated as a presence that has moved into the speaker's body. The speaker feels heavy and numb: blood like cement, bones as flimsy as the zero-calorie jello they once hoped would make them thin. That detail is bitter, since the thing they prayed for has left them hollow rather than free.
The "you" is hard to pin down. It could be the illness, a distorted version of the self, or a person tied up in it. Whichever it is, it lingers everywhere: in the taste on the tongue, the smell of stomach acid on the fingers, an image of skin-wrapped ribs and yellow teeth. The speaker's "oh god, you think it's funny" sounds frightened and helpless. The closing lines are the most unsettling, because the ghost lulls the speaker to sleep, which suggests a grim kind of comfort. The mood is sickly, intimate, and trapped.