Lots of folks here have type 2 diabetes. It can trigger from weight as well as genetic factors, as well as others. My oldest brother has it, he’s skinny, watches what he eats, but genetics worked against him (as with myself and my 2nd brother) and he developed it. He’s able to keep it under control though, as do I.
2 easy ways to avoid it, diet and exercise. I can state it’s about impossible to lose weight from cycling alone, I’ve been riding 30 years and have struggled with weight every mile. You need to burn a lot of calories and need to ride a lot of miles to do that, so it’s hard to do. It wasn’t until I started paying attention to my diet, reducing calories in simple ways (water vs. soda, etc..,) that I was able, this year, to start getting my weight down. The big benefit is it makes cycling more enjoyable, especially climbing hills !. That in turn keeps you wanting to exercise and that’s the positive benefit of the diet plus exercise approach.
A good approach to this is to not think of it as exercise, but exploring. Use the bike to go places you already know about and can now see at a different pace. Go to new places, find trail systems if you want to really get into mt. biking. Go cycling on vacations. It’s fun and doesn’t need be a chore.
So welcome to the forum and cycling.