I just had my consult with the doctor yesterday and this was a specific question I asked.
Basically, a leak from a VSG is very serious business. It doesn't happen often, but when it does, you're talking about the potential of your stomach acids leaking into your abdominal cavity. This will cause severe pain, and you will likely know right away and have to call an ambulance. The doctor said a leak will require a one-month hospital stay.
My doctor said the risk for a leak is minimal (something like 0.01%) but the risk for leakage increases if you are dealing with complications... for example, maybe you've had stomach ulcers, or this is your second procedure after removal of a band, etc. He said among normal patients, the last time one of his patients experienced a leak was 2008. He had two other patients experience leaks in the past 4 years but they were complicated cases to start with, and then they both decided on their own that they were ready for solid foods when they were nowhere near ready.
My takeaway from that is to follow doctor's orders and stick with the approved foods list to a T. :-)