To me its common sense; The body is, and will always be, the ultimate adaptive mechanic.
The body is an accumulation of its passed history, and the body you have at this very moment, is this accumulative result.
One MUST either keep doing what they have been doing (and make adjustments), or set-up a maintenance plan, or lose-over-time-what-they fought hard to earn.
In a sense, you CAN NOT STOP: You lose it, if you do not use it, and the body will adapt, no matter what you do. How fast the regression happens, depends on drugs used (if any), age, activities, and genetics.
If goals are a one-stop-shop. Then your body will never go back to once it was, because a one-stop-shop, never returns. And, if you train long enough, and are consistent long enough, you learn this lesson well, like or not, suck it up, it is life, and deal with it. You have no choice.
Peace and happiness to all of you each and every day.
After losing 40+ unwanted lbs: