The bonds of familial love are tested in Swedish filmmaker Sanna Lenken’s portrayal of anorexia, as seen through the eyes of a young girl who notices her older sister has stopped eating. Geared towards a teen audience, Lenken’s first feature also treads familiar coming-of-age ground with its focus on the pressures young women are under to aspire to a certain body type.

In her debut film appearance, Rebecka Josephson plays 12-year-old Stella and is quite simply outstanding. She delivers warming, believable moments of innocence and joy as we watch Stella practising kissing on a tomato, while her infectious giggle rings out as she tickle-fights with her older sibling Katja (Amy Diamond) and fools about with her best friend. Lenken has created a well-rounded young female character who writes awful poetry in her bedroom, inappropriately lusts over Katja’s figure skating coach Jacob (Maxim Mehmet) and wonderfully expresses her worry for the big sister she so admires. She’s hilarious, spiteful and totally relatable.

As Katja’s anorexia advances, Stella becomes more determined to save her but the stress takes its toll with her glowing persona slowly disappearing in tandem with her sister’s shrinking body and declining mental health. Lenken draws from personal experience (she suffered from the illness when she was younger) but she turns the camera outwards to explore the effect on those close to the sufferer. She doesn’t shy away from the dark, painful reality of an eating disorder and conveys the confusion and angst of it all with a stinging honesty.

The soothing palette of blues and coral is offset by shimmering cinematography, especially in some fluid figure skating sequences. The camera skilfully glides across these kinetic moments and gets up-close-and-personal when the two sisters are bonding or fighting. If Lenken’s script occasionally veers into broad-strokes TV territory My Skinny Sister still marks her out as a promising new filmmaker.

Selected release from Fri 27 Nov.