Hydration.

.. and adding to the discussion, chronic low level dehydration, which a lot normal folks are walking around with WILL make you feel fuzzy headed, and tired. Just 10% drop in hydration can cause this. A little more, headaches can happen.. Most folks today do not drink nearly as much as optimal, just enough to skate by from day to day.. 

I was a water-slammer pre-op (years of recurring bladder infections got me in the habit) and I do the same post op. I can tell when I'm lacking, I get tired. I try for 100oz clears over and above any other beverages I may have in the day. So, prob 120ish a day total fluid intake.

Wow! Thank you all so very much! Incredible. Rob you amaze me, man! All of y'all! I know my B's do add some brilliant "color" I have some other signs of dehydration too like dry skin, but now I know I'm not getting in enough water. I've been getting in about 72-or so ounces, but I'm definitely falling short of half my body weight in ounces. That is so very interesting. The glycogenesis, is fascinating. I read about that in Elina's post too the other day but the pieces just fell together for me i guess....thanks Rob. Makes sense to me now.
All of y'all are awesome. INgirl, you rock!

I will second all that!

 Rob you are so right!

Maybe some of this is coincidence but I drank 15 glasses of water yesterday (I couldn't make 20) and presto. I dropped 4 pounds. This was after having lost nothing the previous day.

I'm a convert. I'll be making sure I'm well hydrated from now on.

Thanks...