CPAP and physical changes

I got a CPAP in late autumn. Took a while getting all the settings right, bed setup optimal, right mask, blabla.

And then I started noticing changes. Not getting up at night to go to the can, awesome. Clothes getting tighter, not awesome. Checked the scale. 5 lb up. So I had to think about it. I suddenly realized that my appetite had increased substantially since getting on the CPAP and that my usual casual low-carbing wasn't gonna cut it. Back to very careful tracking and logging. (I've been logging on another platform that is low-carb-centric because it's easier for me, but I still read here too.)

I do work out, but it's pretty casual because I'm arthritic and get injured easily. I figure consistent low-intensity exercise is better than going gung-ho, getting hurt, and stopping.

Anyway... I googled to see what others' experiences were and I was surprised to find lots of people gaining weight when they started CPAP treatment. Some of them swear they haven't changed anything else, others like me have noticed increased appetite. People also report fewer or no nightly bathroom trips anymore.

I went looking for research, but it's pretty skimpy. I see some stuff about change in blood gas levels and kidneys removing less water and sodium during the night, some stuff about slightly reduced BMR to the tune of about 75-80 calories per day.

Anybody else making adjustments to their diet and routine after getting on CPAP? Observations?