I donate blood regularly, and usually I go off a LC plan for the day. Lately I have felt more dizzy and sluggish into the next day, so the latest time, I ate a large carby meal before donating. I felt much better, and really didn't feel like I had lost any blood at all. I continued eating SAD canteen food as usual, and felt fine the next day. My feeling is that in the past, I wasn't able to get my blood sugar up high enough during and immediately after the donation. Does this make sense?