Isn't that the part about losing weight that just sucks? You can work so hard for a full week and only see teeney tiny amounts of progress. But I know, I know, there are a million reasons for it. I'm about to get my period. I'm bloated from soy sauce and miso soup. I'm sore from my workout yesterday so my muscles might be holding water. But still. Still! When you work hard it's nice to see results in terms of the scale going down. And believe me, I could scoot my butt over to the Mexican place down the street for lunch and gain that .6 lbs back in about ten minutes flat.
Stupid body evolved to hold on to fat in case of a famine.