So on my 5'9" frame the Dr. Office used that funky scale/body fat measuring device where you stand on it and it tells you lean body mass versus fat content. I was a bit surprised as was the nurse I have a lean body mass of 222lbs. Granted I powerlifted for years but that was 25 years ago.

How accurate are these devices?

This means at a 220 goal ending weight, which was recommended by the Dr., I will have a BMI of 32.5.

How much LBM can I expect to lose on this sleeve journey? Do I want to lose LBM? All my experience and research says no, but, well I am in doubt now.

Holy heavyweight Batman!

Great question! I have lost 50 lbs and of those only 6 have been LBM. Right or wrong, I have chosen not to exercise intensely during my losing phase. I'm not eating enough to be able to really build muscle and so have focused on not losing muscle for now. As I get closer to goal, I will likely start lifting again.

For me, I think excessive cardio doesn't help and I know I will lose muscle if I try that, especially since I'm eating between 600-800 calories.

Based on my LBM and my desired body fat ratio (25% which is considered healthy for women), it puts my goal weight at 163 which is not at all normal BMI for someone who is 5'6, but I will never weigh 135 lbs unless I'm okay with losing muscle, which I most decidedly am not.

I think body fat percentages are healthier than BMis for defining goal weight.

As of accurate, I like to distinguish between accuracy and reliability. I don't know how accurate mine is, but if is super reliable.