Surgeon said that the sleeve would take care of the first 100-120 for me with little will power. He said anything above that is up to how well I keep to the program. I think any weight loss tool has the ability to help a 400+ pounder get to a healthy weight. What matters is the execution. It doesn't matter if you are getting RNY or VSG or just counting calories, it is ultimately up to the individual to make the commitment and follow the program in order to lose the weight. I am only one week post op right now but hope to reach my goal weight within 18 months.