Fat Girl (original title À ma soeur!) is a 2001 French-Italian drama directed by Catherine Breillat, offering a raw and unflinching look at adolescent sexuality and sisterhood. The film follows two teenage sisters, the confident, conventionally attractive Elena and the younger, overweight Anaïs, during a family vacation. As Elena engages in a manipulative sexual relationship with an older Italian law student, Anaïs observes with a mixture of curiosity, jealousy, and profound insight, her own burgeoning desires and vulnerabilities laid bare. The narrative builds with a simmering tension, culminating in a shocking and controversial finale that forces a brutal confrontation with themes of consent, objectification, and the loss of innocence.

Breillat's direction is characteristically bold and minimalist, focusing on intimate, often uncomfortable dialogues and lingering shots that amplify the emotional weight. The performances, particularly from Anaïs Reboux as Anaïs and Roxane Mesquida as Elena, are remarkably naturalistic and compelling, capturing the complexities of their characters without sentimentality. The film's power lies in its refusal to offer easy answers, instead presenting a stark portrait of how sexuality is navigated, performed, and often weaponized.

Viewers should watch Fat Girl for its fearless and intellectually challenging approach to a difficult subject. It is a crucial work in Breillat's filmography and a significant piece of European art-house cinema that provokes deep reflection on gender, power, and the painful transition into adulthood. Its deliberate pacing and unsettling realism make it a demanding but unforgettable viewing experience.