Getting back to my original point on weight loss maintenance......IMO, the way we lost it will require that same stuff to keep it off. Meaning, if you lost it doing crossfit with a low carb diet, if you ever stop doing crossfit and indulge just a little, you will regain.

The whole point of creating a solid plan is to be able to continue it long term after you've lost the weight. Do what you'll be able to keep doing.

Being highly motivated to lose excess weight can easily be a factor in doing something like crossfit. Once that weight is gone, you'll need to find a new motivation to keep doing it. Its requires a lot of time and dedication and once that weight is gone, interest wanes.