I was a non-directed donor, but the transplant system in our area kept throwing me together with the recipient who had been chosen for me, so we met and became good friends. The funny thing is, he never looked too sick to me, due to his extra-bouncy, twinkly personality...until the very night he drove me to the hospital for our surgeries, when I noticed how slowly he was walking in the parking lot.
After our surgeries, we were eventually roommates again, and our trajectories went in opposite directions. He kept getting perkier, bouncier, and twinklier, and I...slumped lower and lower in my chair, and grew more and more quiet (most atypical for me). Before my surgery, I already had had a chest cold, and was running a very slight fever. Although I did not suffer, I did not feel like doing a jig right after the surgery. After a few hours, my "partner" ordered his sons to give me his comfortable lounge-type chair, and he took my hard chair. Eventually, as my chest cleared and my temp. came down, I perked up, too, and we had a lot of laughs together.
One thing about my recipient's food: for over a year before the surgery, I'd been watching my salt intake very, very, carefully (to the point that "normal" things taste quite salty to me now), and this watchfulness has only increased since the surgery. On the other hand: when I went back roughly a week after discharge to get my staples removed, his sons were also coming to visit their father, who was still in-patient. They brought a huge shopping bag for him filled mainly with jars of pickled vegetables, each containing more salt than I expect to consume over the next 7 decades. I almost fainted, but then decided that it's none of my business....
Be well, Snoopy