In fact, calories are the main thing that matters. Everything else is secondary. This explains how to go about balancing them. I lost an additional 7 pounds during the shutdown because we removed 2 restaurant outings per week from the equation. No reason to gain it back.
Keeping your Sanity and a Reasonable Weight
How I dropped my weight 40 pounds and kept it off for 31 years without special diets or exercising
Of course, if you don’t want to be soft, then you’ll need to do some form of exercises.