Phrases Talking about Hobbies and Interests

I'm a bit of a fanatic about...

C1

Meaning

I'm very enthusiastic and possibly obsessive about...

Example sentences

John: You've been spending a lot of time at the gym lately.

Alice: Yeah, I'm a bit of a fanatic about fitness these days.

John: That's dedication!

Alice: I know. Some might say it's excessive, but I'm a bit of a fanatic about staying healthy.