I'm 36. I'm still in pretty good shape. The few problems that I have are that I've gained a little bit of weight. I'm tall (6'2") and used to be very slim. I still have a decent body, but I have some belly fat that I never thought I would have. I was probably 150-160 before and now I'm about 180. This might be partially due to diet and being more sedentary because of a traumatic back injury that resulted in a slipped disc, so I tend to be less active. I'm working on changing that with some new hobbies, though. I could definitely eat better, but my fiancee tends to want to go out and with her schedule, doing things like intermittent fasting is really difficult.
I have acid reflux now, which I never had in my 20s. I also feel terrible after drinking more than maybe one beer. It's not a hungover thing, even if I don't get drunk, I feel awful. That probably isn't a bad thing, since it makes me far less likely to drink. I never drank much anyway, but now it is super rare.
Oddly, I've sort of been sleeping better. I used to have really bad insomnia and would need to take something almost every night to help me fall asleep. I fall asleep much easier now, but I wake up in the middle of the night, which I never used to do.
That's about it, aside from some grey hairs showing up in my beard now.