I think you are not drinking enough water. For people who are excercising or involved in sports, the old adage "eight 8 oz. glasses of water a day' is not enough, but this is also true for those who are dieting- especially high protien/ low carb lifestyles. Not getting enough water can add to your fatigue.

Have you heard of superhydration? Some traditional Docs have criticized this, just like they initially criticized low carb diets, but I think there is some merrit to it. I've started drinking almost twice the recommended amount and I feel so much better. My skin is looks better, too. I got a HUGE 64oz. mug and fill it with ice and water and take it to work. I try to drink it before noon and fill it again and drink till the end of the day. The all tease me about it, but I am loosing faster than I was before. Of course, it might be all the excercise I get walking to the bathroom and al the squats I do over the toilet!

Hope this helps, M L

Check out this site- the picture is a bit cheesy, but the info is interesting-
http://www.classicx.com/html/body_2super.html