@dinkydolphin
I am torn here, because I know some people can get very jealous and threatened and pissed off when someone does well for themselves - be that a significant weight loss, or a promotion, or an inheritance or lottery win that makes the person receiving it financially secure (or even set for life...)
Also, some people who lose quite a bit of weight - 2-3 stone plus, can sometimes become very boring and self-centred; talking about nothing but their weight-loss, and healthy eating, and their exercise programme, etc etc. And they can lose friends this way because they are tedious to talk to.
So it may be more about you than them sorry OP. (Tho I don't think a stone is enough for someone to be jealous of - but well done anyway!!!
I have never lost friends through weight loss as I have never been particularly overweight, so have never lost much. But I have lost friends due to doing well in the workplace though. I was very close pals with a woman at work - went to lunch once a week on Friday lunchbreak, went to the pub twice a month, exchanged cards and gifts on birthdays and Christmas.
We were the same level of rank at work, (admin/secretarial,) and we had both worked there 3 years (she started a month before me,) when I got promoted to lower management, with a company car and expense account.
She virtually ghosted me, and wouldn't even look at me. I was shocked and upset as I really liked her and had had some great time with her for 3 years.
Guess people show their true colours eventually.
I did grieve the loss of the friendship though.