I think there is a lot of truth in that. By the time you are approaching or beyond 40, you have a lot less elastin and collagen in your skin. It is bad for anyone to lose it quickly but weight lifting alone will not take in some of the saggy skin - some have to resort to surgery to remove it.

My cousin and friend got the bariatric surgery and lost over 150 pounds each - they now have to get the surgery to remove the excess skin around their stomach and under their upper arms. I cannot say if this was just due to their excess weight so long or the quick weight loss in the beginning (both are almost age 40).

I think the skin cannot adjust to fast weight gain or loss and it is prudent to lose no more than a lb a week (excluding perhaps the first 2 weeks of induction - this would be hard to control).