That's a bad perspective of her. See her lying on the bed in the earlier episodes and you'll immediately see that she's a BRICK HOUSE. Bitch is built thick as a motherfucker. She's the pinnacle of healthy - big and curvaceous but never excessive in any one place. Ok, well maybe her breasts are a bit exaggerated but hey, it's anime.
You can see plenty of guys who may consider that being a fatty, but an equal amount will find her hot.