However...
(1) Abdominoplasty is, compared to others, a TERRIBLE procedure. The risks are great, the scarring is extreme and unavoidable, and -- most importantly -- the patient satisfaction rate is very, very low. Far too many of these procedures are being sold to people who will come to regret them deeply.
(2) While it's true that excision is the only way to deal with large quantities of purely excess skin, my experience has been that MOST people who believe they have "loose skin" actually have a lot of excess subcutaneous fat and no supporting muscular structure underneath.
This subject is a personal one, as I myself lost a large amount of weight a few years ago. I'm a 6'1 male, and I dropped from 260 pounds to 157. At my lowest weight, people thought I was an anorexic. However, as small as I was, I still had a droopy, wrinkled abdomen. I visited plastic surgeons who took one look at my dozens of stretch marks and then assured me that my skin had lost its elasticity. They said only surgery could restore it.
Thankfully, I did not proceed with the surgery. Several years later, I got in touch with an excellent nutritionist and sports trainer. I learned that even though I had shed more than 100 pounds, my body composition was still quite poor -- I was nearly 30% fat! In essence, I had shrunken down to a miniaturized version of my former (fat) self. Now, thanks to proper diet and exercise, my body fat percentage is nearly 10%. And guess what? Stomach is almost as flat as a board! The plastic surgeons were WRONG.
What people often attribute to "loose skin" is, in reality, a shapeless and unsupported mass of fat beneath skin that still has some elasticity. No, the skin isn't tight enough to rein in all that fat by itself, but try approaching 10-13% fat (for a man -- somewhat higher for a woman) and see what the skin can do.
Plastic surgeons make a lot of money selling people irreversible procedures they don't need. It's unethical.