Hi. Please help mee

I would like to find a movie that I saw a long time ago. The action took place in an isolated setting, the children were alone at home. It was about a boy who was forced to eat from his sister who had lung disease. he was forced to do this by some men on whom he takes revenge throughout the film. I remember a scene in which the protagonist eats the cheek of one of the men, and kills the last one in his house with the children.