I bet you weren't drinking water in the middle of the night either!

It's rather common (for me anyway) to be bloated towards the end of the carbup or on the day or two after. This used to be a huge sticking point to me, and I only got over it by getting medieval on the salt and sat fat content. My personal theory, based on what I know of renal physiology, is that it's not just the total salt content but the balance of a whole number of hormones that control water excretion and retention. A big one is aldosterone, which signals water retention, and happens to follow insulin. High insulin causes water retention either immediately or later, because aldosterone will rise and can stick around for a while. This is why ya gotta be careful with high-GI carbs - make sure that they are assimilated by the muscles as easily as possible, with minimal insulin required. Saturated fat blocks the action of insulin, so the pancreas dumps out more - and a flood ensues. This is why those pseudo-smarties with chocolate coating sound like a real bad idea to me.

That's just my theory. Anyone interested in shooting holes in it, please do. Word of caution - I did get an A in physiology!