Compared to my parents when they were 26? Well, my mom is Thai and was skinny as a rail back then. She also smoked (until she got pregnant with me). She's never exercised much as an adult, and it shows... yeah, the skinny-rail look went out when I was born (when she was 34).
So I'd say she looked healthy, but probably wasn't that healthy in reality.
My biological father, he was very healthy at 26, I imagine. He was working on fishing boats as a career, which conditions your body very well. He probably wasn't sleeping enough, but he grew up on the outdoors and loved working outside and eating well. I don't know if he exercised, but I don't know if it matters when you are a manual laborer. Of course, with a job like his, it doesn't matter how healthy you are... your life ends the day you go overboard. Which is what happened to him, 6 years later.
My stepdad has always looked healthy, also because he's a manual laborer and has had muscles his whole life. He was a bit of a hippy when he was 26, though, and was just moving in with my mom at the time to help raise me after my father died. So he was probably smoking shit and not eating that great, then. Still, I think he was healthier at that age, before he started falling off scaffolding (he is/was a carpenter) and injuring his back lifting way too many heavy things. Now he is still doing manual labor but has to take a couple days off once every week or two, just for body pain or headaches/migraines.
As for me, I think my body is in great shape, but I don't eat balanced meals and I have always had a screwy sleep schedule. I haven't been sick in a long time, though, which is a good sign. I'm 5-2" and 130 lbs, work out almost daily (at least 3 times a week), never broken a bone, have never smoked anything in my life, and stopped drinking beyond my limit a while ago (though I only did that for a couple of years, at ages 22 and 24). I think I'm in better shape than I ever have been before, actually, and I hope to stay this way for a good long while! Now, if I could just eat more fruits and veggies...
Oh, and get rid of my allergies... but I don't count that as being "unhealthy," since it doesn't affect my immune system.