I too have a very sticky waistline and scale weight. my body likes adding mass. it doesn't seem to like taking it away. I have had luck with adding muscle, on purpose; adding fat by accident. and, losing either seems difficult at this point.
I have a lot of experience that comports with what some people call, "SetPoint Theory". which is to say, I think there's some credibility to the idea that there are certain configurations of fat mass, muscle mass, and other conditions in the body, that has an effect on hunger and intake which effects mass accumulation. there are underlying reasons (mechanisms of control) why we are the way we are.
in my experience, there is something like an 80/20 or 90/10 split of diet/exercise effects.
exercise effects in general have never been zero for me. but they've never been dominant, or close to dominant.
I've just finished reading Easy Strength for Fat Loss, so ... I'll say that it's of interest that there may be more specific interactions between Exercise and diet that may be of interest, but I digress.
I have struggled with my waistline and the most effective tool I've had is fasts beyond 24 hours.
My most aggressive, most specific fast:
the deepest fast I ever took was about 4 weeks of eating 1 meal of 2lbs of ground beef with some cheese and hot sauce on top, every third day. in the interim, I used carbonated water to drink to preserve my stomach size so I could eat these meals. so. on a 72-hour cycle, I ate a single meal. this was to meet the body fat % for my last contract signing with the army. in 4 weeks I went from 225 to 205, and a waistline of about 40 inches to 36 inches. I was just over 200 lbs. at the weigh-in. and I remember being a little unhappy I didn't get into the 100s, but c'est la vie.
I say all that to say this.
it would seem to me, that there seems to be a step or a cliff, or a margin, whatever we want to call it, where the body will be able to cope with some adjustments to maintain a given set point. and sometimes we need to take a certain metric beyond some threshold amount of change, to get some results going.
relative to your post, I would suggest considering spreading your fasting windows a bit. maybe eat twice one day and fast for the whole day the next on occasion, or more regularly, instead of once daily. maybe consider alternating meal sizes more drastically.
also, I would humbly suggest Dr. Ted Naiman's P:E Diet book. (that's Protein:Energy ratio). I have found it to be of use.
LINK:
The P:E Diet
Experimentation(Anecdote):
Furthermore, I would suggest that, as you experiment, do use a log to look back at your experience so that you can evaluate your results more precisely.
One thing I've found to be a surprise is looking more carefully at my logged info, I may have had a more positive weight loss response when I have a more classical ketogenic diet, than the modern higher protein ratios I use. I believe this has to do with certain specific conditions I suffer from, but a higher fat-to-protein ratio has yielded me substantial weight loss during a previous cut. it could be the case that I'm more amenable to the classical ketogenic formulations for purposes of mobilizing fats. The reason I say that is while I used heavy cream drinks to supplicate my calories during a cut, my waist descended to 35 inches, while my weight was circa 215 lbs. This was around the time they instituted a new rule allowing for weigh-in 30 days after Physical Fitness tests; and I was drinking buttered coffee in the morning, anyway, and ... I was trying out what they call fat fasts. but, as my wife complained. "cream is expensive, Why the hell are you drinking all this cream!?"
anyways. I'll never forget going in to drill with my unit, at the time, I took off my top since we were going to be moving boxes around in supply, and I was receiving unsolicited comments from my peers about how much better I was looking(I remember looking down and noticing that I was a bit more svelt than other times). it was an unusual experience. I was using a "Fat Fast" but, I didn't really know what I was doing, and things changed and I haven't really gotten back to trying that one again; although I'd kind of like to, now. Again, I digress. if you can, Write things down as you go along, and it will help a lot with learning from an experience. I have the benefit of some of my records from PT tests and Weigh-ins with the army. knowledge is power, and memory fails. write it down.
To tie it back: I provide the above anecdote about drinking cream, because this is something I saw when I was perusing my notes I found in a small green booklet in a backpack I stashed in my closet(notes about drinking buttered coffee in the morning and a glass of cream, and remembering about my weigh in, from years ago), and I was cleaning out the backpack, after getting home from getting out processed from the army for retirement (just about a week ago, actually). written notes present a very high-value proposition; even years later. whatever you're doing, if you want to learn from it, write it down.
Do feel free to try something one or two steps away from your current situation, rather than tweaking something in small ranges. maybe in short time windows (maybe a couple of weeks max) to see how a more acute adjustment affects your situation.
And, with all that said about eating, I've been having some positive experiences with small doses of HIIT, as they call it, which, I'm having an easier time dissociating from a puke circuit since reading Dr. Gibala's book One Minute Workout. Its effects on my composition are Non-Zero, but the observations at this point are ongoing, and I'm still waiting to get a clearer picture of the net effects I'm seeing. At the very least, for my small time commitment availability, it's been useful to entertain shorter, more intense workloads, in general.
Link:
One Minute Workout (Amazon) if you're interested.
just doing my best to speak as well as I can from my own experiences.
YMMV
Best wishes in pursuing your goals.
