Romance (I think), read in 2019 about a group of women trying to lose weight

[Gem]

I read this book in 2019, I genuinely can’t remember a lot from it but here’s what I do remember.
It starts with a group of women at a weight watchers meeting (I’ll also add they were all adult)
There was possible conversation of them or one of them quitting.
The main character ends up having a health issue, I think a thyroid issue, which causes her to lose weight. Her personality starts to change after losing weight and her friends call her out on it and she brushes them off as being jealous that she’d lost weight when they hadn’t.
I can’t really remember if this was a rom com, but I think there was a love interest, or at least a man she had been pining for.
I’m sorry if the details are too vague, it’s genuinely all I can remember of it right now but I will add if I remember more. Any help would be appreciated as it’s really starting to bug me, haha. Thank you in advance!