My sister has an absolute fixation with healthy food.
fixation /fɪkˈseɪʃn; US / noun [countable] a fixation (with sth) an interest in sth that is too strong and not normal I’m tired of James’s fixation with football. ▶ mania obsesja bzik
Englisch Wort "utrwalenie"(fixation) tritt in Sätzen auf: