Keep track of AST/ALT over time. Part of how Metformin works is it blocks gluconeogenesis which is basically the process of the liver producing glucose. Most likely if you are relatively low body fat % and have hopefully zero (or very low) visceral body fat, this may not matter so much…

But I’d imagine the higher risk comes into play if you have a NAFLD already.

And yes, you are right about kidney issues, too. My dad was on Metformin for a few years and was eventually diagnosed with some mild kidney issues that were believed to be caused by it, and his medications were changed. That said, my dad is overweight and inactive and diabetic… so his case will be very different if you are living a healthy lifestyle.