What's the best way to get back on track? Had gastric bypass in 2004 lost 140 lbs but gained back 100lbs. Should I just do shakes? Bmi is 49.7.

Diet and exercise. It's not the answer you want to hear, but all weight related matters are due to an imbalance between calories consumed and calories burned. A dedication to a diet of moderation along with a regular exercise regimen will help you achieve your goals. Although gastric bypass helps with weight loss, in the end, it's still dependant on you making lifestyle changes.