1. The girl was so obsessed with losing weight that she eats one meal a day. Eventually she was hospitalized for malnutrition and other health problems.2. My brother started watching Japanese anime at a tender age. He got into it so badly that he is now obsessed with it.3. Do not bear a grudge against others because hate can take you over and make you do crazy things.
 is obsessed with something takes one over「走火入魔」形容過度迷上某樣東西，obsess 就有此意，非常貼切。Hate can take you over 意思是仇恨可讓你走火入魔。
I have been wrecking my brai on this tough math question but I still cannot solve it.