Nathan,
I've had similar experiences. I've never been on a hard-core, low carb diet (ketogenic or not). The lowest I've ever taken carbs, over any period of time on a consistant basis, was 150-200g. I have no energy on anything less.
When returning to higher carbs (normal, 300-400g) I gained a noticable amount of weight and smoothness in the first week.
A) Make sure you keep drinking lots of water.
Since I was eating more food, I was more full, and drank less water. This, undoubtably, caused a lot of retention. I was bloated as hell, as a matter of fact. Returning to drinking water helped a lot.
B) Keep in mind that anything more than a one-pound gain over a week's time is water (assuming no AS use, etc). Even if you DID over-estimated your maintenance calories, there's no way you'd gain 5 pounds in one week.
What can you do? Make sure to drink plenty of water. That's pretty much it. Carbs tend to bloat me a little no matter what I do. Diuretics such as caffeine seem to help a little, but that can't be maintained over any length of time. When you're bulking, I guess you just have to accept a more-smooth look.
Any other p.o.v.?
[This message has been edited by JB3 (edited April 24, 2001).]