I am 110 lbs., I was healthy, no diseases, no problems, last check up, great health.
But, at one time I wasn’t one bit fit. I noticed one day, coming back from walking to my mailbox and back. I was huffing and puffing a bit. I realized, I had no lung power! I was thin, but didn’t have much muscle tone. I’ve changed that since, realizing that about myself.
Yes you can be healthy but not fit. It was determined that an overweight person who is active, will out live a person that is thin and not active. I seen this either on 60 minutes or 20/20, I can’t recall.
So the answer to your question is YES. Yes, you can be healthy, but not fit.