I have been struggling with my weight for a while - mostly up and down some during my 20s (started with the 'freshman 15') and 30s, and the past few years the change in my body due to my age (40s) and medical issues (back surgery, thyroid, hip and shoulder issues, etc) contributed to blocking me from achieving a good level of success in getting fit, though I had some streaks that went in the right direction. A few years ago I was at a good weight, and had good habits. Then I developed chronic and debilitating back issues, and had surgery so my exercise program went out the window, as well as motivation to spend time in the kitchen cooking. I gained some weight even though I would say that my eating habits were not terrible: vegetarian for 20+ years, organic produce (not enough fresh tho), 'healthy' frozen meals, not overwhelming amount of bread/carbs and cheese/dairy, occasional ice cream or fast food (maybe once a week). I recovered and went back to the good, stricter habits. The small amount of weight loss was slow, and it was hard to build momentum due to setbacks from all sorts of outside (and inside) influences.
I never really wanted to do a 'shake' diet. My thought was that ok, you lose some weight. But once you achieve your goal, come off the meal replacement shakes and stop being super strict, what's going to prevent you from boomeranging into unhealthy behavior? Well, I changed my mind. I believe that my body is different now, which makes it harder to take the weight off initially, and am confident that once I get down to a healthy weight I (and my hubby) will be able to consistently establish my prior healthy program and stay where I want to be.
post script - it was not the right fit for me. I felt very ill (not the way you feel when you do cleanses, my body was rejecting the shakes, etc) for 3 days, and felt very shaky before I stopped.