Welcome Paco,

I have 14 UKs and one of the reasons is that flexibility. First, hope you got your UK sized to wear under your belly - if you got one. That part doesn't change size as drastically.

There's also flexibility from the top snaps up, the waistline has a couple inches give back and forth.

I'm back and forth over a 15 pound weight range and my same UKs still fit.

Ron