Pro athletes say that 5-10 lbs gained "back" in the offseason are no problem as long as training for the new season occurs-- when the "extra" pounds will melt right off on their own. The annual cycle in that gain/lose range is normal for them.
So TRUST that one's normal season of highest activity CAN keep one approx. where one is.
There is also the good news that a speeded-up metabolism due to muscle-mass increase will last 6 weeks, so a short layoff from vigorous activity is not a crisis.
On the other hand, athletes who take a layoff say that anything longer than 2 weeks will need to be rehabbed and/or retrained back up to the pre-breaktime level.
They ALL say that as we age, we FEEL the breaktime loss of muscle-flexibility is felt in function, sooner and sooner.
There is also info out there that the slower the weight loss, the better for our health, and that periods of loss followed by periods of maintenance are GOOD for us in many ways.
One way I monitor all that is that I own ONE pair of "fat pants" that can be worn when my tummy's acting up or I have all-night-sitting to do. They fit like pajamas. I have FOUR pairs of jeans/trousers that are snug. The day I have to put on a pair of fat pants to do a non-fatpant activity comfortably-- that's the day I drop everything and get back to the pool NO MATTER WHAT, and I stay on the pool schedule till I feel so damn fit I want to get out of the water and DO stuff. Then I slack off pooltime in favor of land-based muscly work/fun.
In the high-activity phase I eat (healthy) when I'm hungry, day or night. I'm feeding a fast metabolism. In the low-activity phase I eat as many tiny (healthy) mini-meals as my shrunken tummy requests, because I am feeding a metabolism that may slow a bit.
Because the MAIN thing that gives me feedback is my tummy. Now that I don't fight with it any more, it gives me good info on when to stop, and it hurts if I ignore it. :~)