ELI5: Why has one of my feet become a larger/wider shoe size than the other?

When I was 19 I was 101 lbs (5'6"), by the time I was 30 I was 287 lbs. I also carried a pregnancy during this time. My feet went from a size 8.5 regular width to a 9.5 wide. I'm now 99 lbs down from my high weight and I find myself in a dilemma: my left foot is a 9 wide, and my right foot is a 8.5 regular width. I do not have a medical condition that I would think would cause one for to be larger, although I do have plantar fasciitis in both feet so maybe that could be a factor. My left foot doesn't appear meatier or fattier, it just looks like the bones and muscles are more splayed out. Can someone explain how large weight fluctuations and/or pregnancy can cause uneven foot size?