I was diagnosed as T2 diabetic around 18 months ago, so my diet adjusted accordingly. Dropped the majority of carbs in my diet, started running a lot more. I had a bout of illness around November/December last year and lost a fair bit of weight that dropped me a jean and t-shirt size. I've managed to keep to those sizes too by just applying common sense to what/how much I'm eating, even though I've not been able to run anywhere near as much since that illness.

I wouldn't recommend it as a strategy tbh but it's certainly forced me to make choices for the better!