The blood tests came back normal; it's still a bit of a mystery. I admit that I eat less than I used to, and my appetite adjusted itself accordingly, but I don't think it's that much less. Sometimes I will take two bites and be full; sometimes I will eat normal serving sizes (I think).
Guess it's time to keep track again. I started that last year when I first got concerned, but it becomes so easy to forget. Maybe I will keep notes on the side of my work tablet. Still have a follow-up Thursday.