I've also experienced increased levels of appetite after a chain-vape session (8mg, 100% VG). I don't think the symptom is indicative of any serious ramifications. I do make an effort to stay well hydrated, especially because my job is highly physically/mentally intensive.
I'm not exactly sure it's related to vaping in particular, either. Could just be a side-effect of quitting the analogs, which is a usual response. I know this is generally attributed to the nicotine, but with 2,000+ (?) chemicals in each stick, other factors could certainly be involved.
My advice: Drink more water, and snack on some cheese