Cool Leslie---we're about the same helght/weight! I get the lightheadedness when my carbs are too low. I usually up them a bit the next day and feel better...one day below 50, one day above. I've only REALLY been tracking for a week or so---but been eating primal for awhile. What is your goal weight? My lowest weight ever was 118 and that was back in my juicing days....felt too thin though. 125 would be lovely for me though! best of luck!