That sounds very, very low to me unless you are a really tiny person! I struggle on less than 1800 - 2000 cals a day, more if I exercise hard! I'm around 5ft 5 and 140 pounds but I have always struggled with keeping my blood sugar on an even keel and need to eat quite regularly. Where are you getting the calorie counts from?

I have also just re-started taking note of everything I eat again as I have put on a few pounds lately. I use fitday (www.fitday.com) which is a free online tool. I like it because it gives you the breakdown of your carbs/fat/protein for the day as well as overall calories, I tend to eat a diet too high in carbs at the expense of protein and fat and this helps me balance things a bit. I used it a lot last year and looking through my entries for then it seems that 2000 cals was generally the magic number for me to train reasonably well and still lose weight (except for my long Sunday MTB ride, I ate as much as I wanted then).

There is a BMR (Basal Metabolic Rate) calculator on the concept2 (http://www.concept2.co.uk/training/bmr.php) website that gives you an idea of the amount of calories you need daily. It uses your sex/age/weight as a base then you add on your activity level, my calculation came to 2700 a day.