Food is the subject here, but the poem is really about a fight inside the speaker. It begins calmly, almost like a person reciting rules: overeating is bad, I don't need more, I can live without it. The repeated "I know" and "I'm fine" sound like someone trying to convince themselves. Then the tone breaks. "I'm hungry. I can't stop it." The short, controlled lines give way to a rush of wanting, with "I want all of it" and the endlessly repeated "again and again."
The speaker seems to feel torn between reason and compulsion. Eating is no longer pleasure, since they continue "even if it's bad, even if it's poisoned," and the food is called "torturing." The mood is anxious, desperate, and a little shameful. The ending turns outward, as the speaker snaps at someone watching and insists "you are like me." It reads as a defensive, uneasy plea for recognition.