It kind of depends upon what you consider non-invasive. Some folks consider liposuction to be non-invasive, whereas for other folks, they're really talking about some of these external devices that will cause skin shrinkage. I think it in part depends upon how much laxity you have. Where you are in the aging process, the quality of your skin, what your goals are, and what your risk tolerance is. If you have a minimal degree of a problem, then it's possible that a non-invasive treatment might work for you. If you have something more involved, well you might be able to try a non-invasive treatment but you might be unhappy with the results. I personally have yet to see, really, a lot of positives about the non-invasive treatments, but there are a lot of people that are happy with it, and they feel they've gotten what they want out of it.
Non-Invasive vs. Surgical Body Contouring
Dr. David Kahn discusses options of body contouring based on how much of a pain and risk tolerance the patient has.