Hi RB,
Sorry for only replying now pal, but was unable to do over the weekend as we went away for the weekend, and then the wife is strict on using any form of technology
So I'll also start of by saying I'm NO expert on reverse dieting, although I have twice done it and increased my "Body Fat set point", once I dieted a few weeks for the sole purpose of reversing it to find and then increase my metabolic rate and body fat set point, which I found easiest to maintain with my lifestyle at around 8%BF and 3230Cals. (I'm on cycle now, and doing a little under 3600cals/24h, but will also have to find my set point again after my cycle as I have added some good muscle) So my opinions and advice is only based on my own experience, implemented over the years from reading up on studies, and advice from friends in the industry.
So our bodies sole purpose at the end of the day is to be healthy, to be able to stay alive as long as possible, and it will do whatever it have to in order to protect itself, even from its own mind.
So let's start with your Macros, I have thought about it over the weekend, and think that it's a good idea running a more balanced macro diet if you will stay under BMR for a prolonged period of time. I prefer and normally advise low carb diets for Rapid weight loss. But I have not read enough studies on the health Aspects regarding Maros on Starvation Diets for prolong periods of time to advise much more.
With that said, at the end of the day, caloric deficit is a deficit, and if you are giving your body less than BMR, it does not matter so much what you put into it imo, you will force it to start digging into fat stores as energy, or eventual muscle if you don't have enough fat anymore. But I still believe eating balanced then is healthier than eating only 1800cals a day worth of only say chocolate or only Meat, and getting in only one Macro in Carbs or protein. Thus I think running at 1800cals like you intent to, with a balanced approach is a better option than only a Low carb diet. But because your metabolic rate will slow down, and eventually start to or stop losing weight or lose to slow for your patience, you might have to mix it up in the end, start off balanced and later run low carb, as the low carb high fat diets is a little better for the hormone production to reduce down regulation. I would also cut meal sizes and eat 7 or up to 9 times a day, to keep your metabolism going more.
Before we discuss reverse dieting we have to understand the reason why we do this. When we use Starvation diets, our bodies realises there is a gap in the energy needed for MBR and the current intake. So what it will do is slow down almost all aspects of our bodies, our metabolism adapts and decrease the amount of calories needed, it becomes slower, even our organs start using less energy, the hart rate will slow down to use less energy to decrease the amount of Cals burn during the day performing normal tasks, and biggest issue is our hormone rate slows down, down regulating mainly T3, Test and Leptin, thus effectively reducing our BMR, but now with less hormones which often then adds to the problem of feeling kak while on a starvation diet. Also partly why I would say running a cycle of Test and/or SARMs is possibly not a bad idea, as you will at least keep your hormones better balanced even while you are on extremely low Calories.
When you approach your goal weight or look, is when reverse dieting comes in, to re-teach our bodies to use more calories again, increasing metabolic rate again so that we can ultimately eat more
. Now the problem comes in if we don't do this and after we reach our goal weight, we go on binge eating sprees as we have cravings because of the deficiencies in our diet for the last however many months or weeks it was. What our bodies then do is instinctive, when we suddenly give it much more calories than what it was use to, it still now needs fewer to function as the starvation lowered your BMR. Now it sees all these extra Cals and grabs on to them, and stores them in the form of fat as it is scared you will starve it again tomorrow, then it can at least use this extra fat to burn as energy to make up the gap tomorrow. This is often why people that go on a quick fat loss starvation diet for a few weeks, lose weight, then go back to their old "normal diet" but then pick up the weight again, because now their bodies don't need the same amount of calories anymore to complete all the required bodily functions in order to live, and you are now overfeeding it.
So there is two ways of doing the reverse diet, slow or fast. Obviously the slow method is more effective as you limit the amount of fat the body stores when you start giving it a surplus of Cals again, but also takes more discipline. The Faster method also works fine for normal people like us that are not coming of 6 months or longer extend periods of dieting for a show, and then having cravings for Big Macs, McFlurry's and Pizza at the same time.
But in your case the middle approach I think would work best, start of faster, then slow it down. reason I say this is because of your stats. ATM quick calculations gives me your BMR is around 2140 and Maintenance cals is around 3200+ depending on daily activity, but at 82 kgs your BMR will be around 1812 and Maintenance 2718 (activity level only multiplied by 1,5), and you will run a diet at 1800 cals, leaving us with a deficit of around 1000cals. (My Body would hate me and kick my arse) but we are all different and as you said you have done it, and will go on feeling, you will find out soon enough if your body starts to say "enough of this" I need more.) Normally Reverse dieting would do a initial increase of around 15%( +-150 cals) in this case in the first week, and then go up 5% (42cals in this case)each week. This would mean in your case you would need another 20 weeks after your weight loss diet, this is too long, and thus I think a 25% initial increase (250Cals), then around 100 cals a week would be good, leaving you with another around 6-7 weeks to reach your Maintenance level again. 6-8 More weeks might sound long, but by then you have reached your goal, are most likely happy and should see this as an insurance policy to help maintain that body and look.
If you do decide to do a Low Carb diet later, and you go into the reverse diet after this, I would say change your diet then back to a normal year round sustainable diet with all three Macro's balanced, and increase Calories at the same split. So if you are then doing a split of say P40%, carbs 35% and Fats 25% and you weekly increase Cals by 100, Increase by 40cals Protein, 35Carbs and 25fat.
You would need to weigh yourself every morning, to keep track of what the calories is doing, if you keep losing weight, you increase a little faster, and if you see you start gaining then you increase less, and less until you get to the point where your weight stays the same, and then you know, OK, my Maintenance is exactly say 2700Cals. You can then even do fine tune reverse dieting, where you increase Cals by like 2% a week, which your body will not put into fat, but will learn to use to make up the surplus gap to burning ratio, and thus increasing your BMR and so also your maintenance, allowing you to eat more and stay at that weight, which in turn in future will mean you would not likely want to go on binge eating sprees as your body is fully satisfied and you would not have real hunger issues.
Like I have said, while dropping weight, I would personally decrease the amount of lifting you do, and increase cardio, and as you approach your goal weight, start to turn that around, increase lifting, and decrease cardio to the point where they are both what you would be happy with to sustain as soon as you start the reverse diet. So that when you reverse and try to find that specific caloric need for your body Fat set point, you already do the amount of lifting you would continue doing in future as well as the amount of cardio you would sustainably do year round, so to not increase or decrease your energy expenditure much as you approach that set point.
I hope this all makes sense and helps, tried to best explain I possibly could, even though Endomorph had already explained it all and you probably understand the principal already.