Interesting. I just listened to the Security Now guy (Steve Gibson) who has been going super low carb and has done a couple of geek specials on the subject. Very good information in the two podcasts he did. Here's the link to the first one:
http://twit.tv/show/twit-live-specials/124
If you have a lot of energy problems during the day -- besides exercising, going completely very low carb is a good way to even out the post-carb crashes that plague lots of people like myself.