Each individual is different. We all have different metabolisms. It's good for some, but not for others. My mum can't diet because she's too old and has a disease.

I think it depends. Humans have different metabolisms, what may be good for one person might not be good for others. For instance, my mom. She cannot diet because she's old and also because she has a disease.

I think it depends on the individual - humans all have slightly different metabolisms. What might be good for one person might not be good for others. For instance, my mother can not eat certain foods because she's elderly, and also has health conditions which restrict her diet. Keep working on your English! You can do it!