Although you might see initial quick results with your daily calorie count set so low, a lot of women have experienced weight loss slowdowns if they eat fewer than 1,200 calories a day--especially if they're already at a healthy BMI (as you are
)
and are engaging in regular exercise like running. With that few calories, your body tends to think something is wrong (like famine) and wants to hold on to as much as possible, so your metabolism can slow down. So when you ask if you should do something different, I'd say yeah, think about increasing your daily calories. I know it seems counter-intuitive! Did you jump right down to 1,000 calories or did you have a different range before that?
Incidentially, I find I have LESS of a desire to have "cheat days" when I up my calorie count a bit and it is much easier to
1. Eat multiple times a day (six or so)--which will speed up your metabolism
2. Push yourself in your workouts (I'm a runner too, so this benefit is really great).
3. Meet your nutritional needs (the lower you go, the harder it is to fit in everything that your body needs)
4. Maintain your weight loss (go too low and when you reach your goal weight and add a few calories back, your body will pack on weight because it doesn't know when the next "famine"--a.k.a, starvation diet--will occur).
Good luck!