Weight loss is a lot easier with a CPAP if you have sleep apnea though. Unfortunately, I’ve personally got a double (or maybe triple) whammy with sleep apnea and narcolepsy. Narcolepsy trashes your metabolism and improperly treated forced me to eat something to stay awake when I needed to run errands. Every time I’d diet my metabolism would plummet and I involuntarily sleep a lot more. It also impedes the body’s abilty to heal (including recovery from excercise). Narcolepsy is caused by part of the brain becoming damaged (attacked) by your own immune system, unfortunately sleep rhythm, metabolism, and healing are all controlled at least to a degree by the same part of the brain. Fortunately, my doctor put me on Adderall (which was literally the last drug left to try for it), and I no longer have to eat just to stay awake when running errands... I’m dropping about a half pound a day on it. Overly strenuous exercise might still kick the crap out of me, but I’ve at least got more energy to get in some walking.
Thanks for the mention of “orexin”. When I was involved in neuroscience research decades ago a new concept was neuronal drop out due to toxins actually created in the neurons themselves as a possible role in the production of diseases like Parkinson’s. I wonder if something similar might not be happening with orexins. Interesting.