Healthy is all relative. Usually the answer is no, but people like Tesla and Einstein rarely slept. The right answer is make sure you are getting some sunlight.
Hey, ever hear of the Uberman Sleep Schedule? Its where people only sleep 20 minutes every 4 hours and go through the day as normal. I believe Da Vinci used the Uberman Sleep Schedule.
I'd say no, as you get older you don't need as much sleep (generally) but it only gets down to like 6 hours when you're about 60.
Toront is right though, healthy is relative. I used to eat 6,000 calories and do light work outs, I was healthy. If I did that now, I'd be unhealthy.
That's why you're balls will be bigger! Massive, in fact. Some might say too massive, but those people are just beta cucks anyway, so don't listen to them.