Well, thinking on the subject at a nutrition level: the sugar carbon hydrates are absorbed to your system threw your stomach and intestine. Yes, some of the "vapor" may go to these organs, but that is so a few portion, and considering the portion of sugar that a e-liquid may have, i believe the influence would be just near to none. No proof at all, that's just my 2 cents.
Regarding the loss of appetite, well on the contrary now i stop analogs and start e-cig i have more appetite. But when i smoked analogs and i was hungry but still waiting to eat or something, i would smoke more. My hunger would raise but my appetite by itself would lower, hope you understand what i'm saying...