Although a good water intake and exercise will help, I'm afraid if you're gonna get it, you're gonna get it. It's similar to stretch marks - some people do, some people don't. I'm covered in the silvery little brighters. I'm in the over 40 category too.
In total I'm over 8st lighter than my heaviest weight and having gone up and down A LOT over the years, I have more skin than I know what to do with. I strive to have Crystals mindset on not letting it bother me, but it does..... massively.
BUT..... would I rather be edging towards 19st and a size 24 or 10st 11lb and a size 10?? Think you'll know the answer to that. Baggy skin doesn't make me unhealthy and it won't shorten my life - excess weight is unhealthy and will shorten life.
Sorry, that's no help at all, but it is realistic.