Hey there, Heather -- I thought it was related to poor diet, poor circulation, and excess fluid retention. I also was under the impression that it was reversible with.....surprise!.....improved diet, increased physical activity, increased water intake and reduced sodium intake, and the weight loss that would result from all of the above. I'll look into it, but that's what I thought.
The key is that you continue to improve on these areas. (1) You're already working on the exercise -- once your knee gets better, you can try doing that tape more than once a day.....you shouldn't push yourself to do more than you're able during a session, but there's no reason not to try it twice a day instead of just once. And just add to your general activity a little at a time as well. Get up and walk around just for the heck of it; take the long way to get to where you're walking; take the stairs and pause for breaks if you have to. Just stay concious of increasing your activity levels as time is passing. You'll find that the more you do, the more you CAN do. And if you've got Edema, your body needs it. (2) You are making dietary improvements -- the elimination of soda comes to mind, and that's great! Now maybe you can look at decreasing your sodium and fat intake or making some other improvement? (3) You referred to increasing your water intake -- that's great too -- and very important to reducing the effects of edema and more. Just open up your mouth and chug-a-lug! Challenge yourself to increase your intake till you reach the recommended amount. You don't have to do as much as this if you don't want to, but some of us (myself included,) drink 120-160 oz. per day. I swear it helps me with my loss and also fluid retention.
I'll see what else I can come up with....but I believe this is a pretty common byproduct of morbid obesity, and is completely treatable.