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。
My sister is bad-temered and would snap at anybody whenever she feels like it.