So I've read many times in many places that whens someone is 'new' to exercise/decent nutrition they may experience both fat loss and muscle gain at the same time when combining exercise with a caloric deficit, but generally speaking you aren't going to build any muscle with a deficit and you primarily experience fat loss. Weight training gets incorporated into a fat loss program with the goal being to maintain what muscle you do have while losing fat. Got it- makes sense.
So, roughly speaking, how long is someone in that magical 'new' zone?
I am 29, female, 5'4" @ ~140lbs. I have exercised on and off (mostly on) for the past 6 years. For the past 6 months-year, I was probably consuming anywhere from 1500-2000 cals daily and excercising 3-4 times a week, using mostly weight machines with some challenge, but not an all out challenge and moderate steady state cardio. I lost a good 15 pounds slowly during that time, but still have plenty of extra fat handing around my midsection. For the past month though I have been eating more along the lines of 1300-1500 cals most days and excercising 5 times a week with 3 heavy lifting days (full body routine). In that month I've gotten smaller and have much more visible muscle tone, but the scale has dropped a mere 2 lbs. So I'm clearly still in that magical 'burning fat/building muscle' zone. I'm just wondering how long (roughly) this might go on. A few months? Half a year? A year? I know there is no set number and I'm not expecting an exact answer, I'm just wondering based on other's people's experience how long that lasts.
My primary goal is to lose fat, long term goal is to build muscle. Since I really enjoy weights and loathe cardio, incorporating heavier weights has been good for me personally, and while I do like the results I have I'm having a hard time being grounded and not getting hung up on that number. I've never been much lighter so I don't have any real end weight in mind but can tell I'm clearly still carrying many additional pounds of body fat. I'm growing paranoid that I'm not on the right track
long term for fat loss and that I'll just start building muscle but maintain my squish.
Also, my regular life is completely sedentary- I work a desk job from my house. And yes, I have finally incorporated at least one 30 minutes HIIT session per week

I recognize I'm probably undercounting my calories so I always round the daily count up and try to round my portion sizes up as well when tracking.
Thanks!