(23M) Losing attraction to my (23F) girlfriend due to lifestyle differences — how do I handle this?

My girlfriend (23F) and I (23M) have been together for almost 3 years. From the beginning I made it clear that staying physically healthy and active is very important to me in a relationship.

Over time, she hasn’t been consistent with workouts or physical activity despite me trying to support her by getting gym memberships, trying sports together, and running. It’s become a repeated cycle of starting and stopping.

She has gained about 30 pounds during our relationship. The weight itself isn’t the main issue — it’s the lack of effort toward change. I’ve had multiple serious conversations about this, including one three months ago where I told her I couldn’t stay if things didn’t change and that she had to want it for herself. She said she did, but I’ve seen almost no effort.

She’s an amazing person and I feel guilty for feeling this way, but my attraction is fading and I’m conflicted about what to do next.

TL;DR: I (23M) feel myself losing attraction to my (23F) girlfriend due to lifestyle/health differences. I love her but don’t know how to move forward.

Question: How do I decide whether this is something I should keep working through or if it’s a fundamental incompatibility?