Why can't people SEE these things??
I know you're being tongue-in-cheek, but this brings up a good point.
The human brain has evolved into an outstanding pattern matching machine. In fact, it's _so_ good at matching patterns that it has a strong tendency to make-up patterns when none exist.
Most of us, self included, haven't been
vaping long enough to find any metabolic "change". Metabolism ebbs and flows, and there are many things that contribute to it. Over time patterns emerge. But not over weeks. Seasons? Probably. A couple months? No.
I can account for very nearly every calorie that has gone into my body from 1987 until ~2hrs ago. With quite a few more gaps - my blood pressure and heart rate sampled several times through each day. [a training habit I got into early in cycling. I'm really rather subject to forming habits, I think...

] My metabolism could be said to be down substantially since I started
vaping. Coincidentally - that's the same time my cycling season ended. I've gained a fair bit of weight - but the last two weeks my metabolism is starting to "wake up" - and the weight is starting to drop off. Gosh - how does
vaping fit into that model? Could be the 400+ miles of riding this week, and effectively coming out of my "hibernation". [I'm pretty bad at maintaining off-season training].
Patterns are beginning to emerge that as I approach 40, bringing my metabolism "back online" takes longer and that it doesn't peak at the levels it did when I was in my early 20's.
The point is: this is a long-term play. Don't look at today, look at the data over the last six months, a year, five years... And look for other cause-and-effect (like #hrs spent in front of the forum this month that would have been spent walking the dog this month last year, for example).
Jazzguy - I'll forgive you because - MahHa! I don't look like Cindy Crawford either! errr - wait. I never said I did. [shrug] Congrats on dropping that extraordinary amount of weight and committing to get and remain healthy!