MarcyL,
Food logs are the bomb, they have really helped me in the past. I wish you all the best with your knee replacements.

I almost went that route (bad knee issues...bone spurs, bad arthritis and more), but was very high risk for having the surgery done at the time (due to my weight at that time). The surgeon I saw was awesome, told me that many of his patients managed their pain by their weight. When I realized the pain that had essentially disabled me for several years at that point, was potentially within my power to alleviate, I began that 4 year push to lose it all.

He was right, I got off the Relafen I had been on for about 3 years (too long!!!), ditched my cane, and while I will never jog again, it has been sooooooooooo much better re any pain. Still unstable, still sounds like broken glass crunching away in one knee, but they work

You might want to consider starting a journal here, I find it very cathartic!