@Mrmik - I've gained 22lbs. since quitting smoking and going to vaping only in Jan. 2014. Went from 1 - 1 1/2 PAD for 42 years, to vaping 6mg eliquids. Did not change my diet at all (the amount of food I eat, the types of foods I eat, when I eat, etc.), the amount of exercise I get...nor anything else. I also take thyroid meds, but had been on the same dosage for the last 23 years, with my weight never changing more than 2-3 pounds up or down, in that time period. Then I quit smoking, and in the last 2 1/2 years have gradually added the 22 pounds.
My endochronologist won't change my meds to help with the weight gain (nor other symptoms I'm having related to thyroid issues now that I quit smoking). He told me that quitting smoking changes your whole metabolism. That's why even many people who didn't replace smoking with eating more, nor eating snacks and other things as smoking replacements, will still gain the weight. So...maybe that's what's happened to you, too!
Since he won't adjust my meds, I'm considering raising my nic level in my DIY eliquids. I want to see if that makes a difference in my weight, and in my energy level that's been way down since quitting smoking.
I'll be interested in hearing if your weight changes if you adjust your nic level.
I decided to track my calories in/out about 3.5 years ago using myfitnesspal (recently switched to fitbit) to try and lose weight and have went down from 210+ to 147 as of this morning. Switching from smokes to vape 14 months ago did not slow down my weight loss at all but I am meticulous about weighing my food, and tracking my exercise/steps, to track my cals in/out as accurately as possible. In fact I had a hard time trying to maintain my weight when I decided 150 was where I wanted to be over the past winter and got as low as 140 before I started using a step tracker on my wrist (used to just use my phone to track longer walks and bike rides) to more accurately track my daily calorie burn.