General

There are so many variables. Physiology, genetics, musculature, etc.
You may have issues with knees or lower back depending(I always exercised to strengthen and increase fitness even though I'm fat)
If your fitness is low, then you will certainly notice a difference in breathing and blood pressure. You may tire faster or give out of breath faster.
You may chafe and have friction issues where thighs or fat rolls rub.
Also stay clean at all costs.

You can overcome and adapt, or you may not have any significant issues other than being slower and hungrier lol.
I like to keep my health AND fetish

Good luck to you both and much fun to you!!!

After I exceeded 215 kg I had a rapid change in mobility walking is really an effort. And the underfoot pressure is noticeable and limiting on standing time. 20 min max. Fat between the legs has we wadding and with wider gate this increases loads on the legs. I have difficulty rolling over in bed, and have to sleep raised a bit due to stomachs weight. My hips have gotten much fatter and wobble significantly with each step this can effect balance at times. Account of my bigger belly apron pushing on my thighs climbing step means pushing my belly up and down each step that's hard work.

Interesting. How do you feel about that?