If your pants are looser, you probably are losing weight. I'm really bad about constantly weighing myself (twice a day or more) and writing down my weight. I eat, then run upstairs and weigh myself. It's pretty strange, actually...

Oh yeah, I sort of forgot your question there! You said you've been restricting for about six months, which is definitely long enough to lower your resting metabolic rate. For example, I'm 5'8" and.... sort of heavy... so my resting metabolic rate is about 1600 calories a day. However, this number is affected by exercise, body temperature, illness, and diet. Six months of eating 500 calories a day (or less) will crash your metabolism, especially if you're consistently restricting or fasting without any binges in between. Your body enters starvation mode and, literally, begins to shut down. Your resting metabolic rate could slow to 900 calories a day; for someone like me, I would have to exercise off 700 calories just to match my old restingmetabolic rate. And if I'm only eating 500 calories a day... Well, let's do the math:

One pound of body fat is 3500 calories. Therefore, if your RMB is only 900 calories and you do no exercise, you are burning 400 calories. If I had not crashed my metabolism, my RBM would be 1600 calories. Therefore, I could eat 1200 calories without any exercise and still burn 400 calories every day. If you burn 400 calories a day, it will take 8.75 days to burn 1 pound of body fat.

Also, if you exercise off 700 calories a day with a 500 calorie intake... That's -200 calories a day. Let's face it, a car can't run without gas...

What's really sad is I know this, yet I still struggle to eat healthy. Our bodies will only take so much punishment, right?

Hope this helps...