Lonely Mouth by Jacqueline Maley

Matilda knows about hunger. She works in one of Sydney's buzziest restaurants, Bocca, while suppressing her cravings - including for her celebrity chef boss, Colson. Everything in her life is tightly controlled: she allows herself one weekend a month to feast and purge, the rest of the time, she stays perfect. Until her younger half-sister Lara crashes back into town, stirring up the family's chaotic past and bringing long-buried secrets to the surface that threaten to disrupt Matilda's carefully compartmentalised life. 'Lonely mouth', he repeated. 'It's a Japanese expression. It means, like, you feel like you want to eat something, but you don't know what it is. You're looking for just the right thing. But maybe there is no right thing. Maybe you don't need anything at all. But you can't tell'.