I had stretch marks and saggy stomach from my pregnancy 12 years ago, I am 33 and I did have a bit of a double chin before the fast. Since the fast my face is tight, very tight, and thin, and my stomach tightened but the skin is still quite loose. Maybe if I went a bit longer. The skin under my arms however(you know the wave arm) has shrunken and disappeared! I am very impressed.
Please keep us updated on the skin issues, I am very interested to know if repeated fasting will help with this issue!