It is complicated but I would be happy to do that but... here is the thing..

As you reduce your calories and say lose 30 lbs... my BMR reduces. I think perhaps substantially. So my last major diet I was left having lost weight but I could not eat more than a certain amount or I would gain, and gain fast. At this point you are kind of trapped. Living in the world you cannot completely abstain from high calorie items. And if your metabolism is so suppressed that 1 brownie can make you gain weight, then you are in trouble. And that was the way it was. It is also difficult for your metabolism to go back up if you are eating a small amount.

Also, once you get to this point, whether it is your body or your mind, I find that you are made more hungry. So it is easier to slip.

In 2012 to 2013 I lost weight but I also made it so eating more than 1000 calories would have me gain weight. For over a year I struggled to keep eating that small amount of calories and finally I got sick and could not focus on it, and gained 15 lbs in a 3 week period. And I could not lose it.

I gained it all back. Physically there was no choice.

A few years later, I tried another diet and was depressed to discover that after 13 weeks the exact calories that had resulted in weight loss.. no longer did. The diet people told me to eat less and exercise more.. but I knew that was a recipe for disaster. As I would just end up in the same position I was with the other diet. Suppressed metabolism.

So knowing this I tried a 13 week loss period to be followed by a 13 week eat normal period, but when I ate normal again I did gain too quickly. So that means that my metabolism reduces in the 13 week period.

I have had my metabolism tested three times and the basic amount they say I have is 1550 cals -- this is at my full weight after a period of eating normal. So if my metabolism reduces by just 20% that drops me to 1240. If you happen to have a higher metabolism and go on a diet and drop 20%, you might not notice because you have this higher metabolism and would still be losing.

So I am going to try one new thing , it is going to be eating less for two weeks and eating maintenance for two weeks. The goal with this is to keep the metabolism from reducing. I read a study that did it this way and people lost more weight than just regular dieters because the metabolism didn't reduce. This will make for very slow loss... but, likely, it will avoid gaining it back because your metabolism will not reduce.