That's just one approach.
There are other ways like eating more frequently.
But more powah to ya if that worked.
As for lydia, I pm'd you so check it out.
You are not eating enough food for you body to drop any weight. I know that sounds counter intuitive, but this is the way it works. If you are burning 1000 calories and day, and only consuming as much your metabolism has slowed in order to keep you alive. You are going to have to force your body to burn ANY extra calories- thus chaining yourself to the treadmill.
In order to lose weight you have to eat three meals healthy meals a day. You must eat BEFORE your workout, consume proteins within 45 minutes after your workout and make sure to eat a small dinner. In order to lose weight you have to feed yourself. The more calories you burn, the more you should eat. Initially, as you begin to eat more, you may gain a little, but soon your metabolism will speed up and you will see a huge difference.
All the info I gave here came from my personal trainer at my gym. I was in your boat a year ago. Now I am 2 inches smaller than my wedding dress size and I weigh 123 lbs. So this does work.
I agree that you should get your thyroid checked (not just TSH; get both Free T3 and Free T4, also); while you're at it, also get checked for insulin resistance, and have your reproductive hormone levels checked.
Then as OytheGreat says, 1000 - 1500 calories may not be enough for you. You have to provide enough food to satisfy your basic energy requirements (heart beat, lung and kidney function, digestive processes, etc). If you don't, your body won't let go of the fat.
In addition, it's possible that going to the gym is building muscle, which is denser (more compact) than fat, so again, as OytheGreat says, try measuring yourself and see if you are getting smaller.
You may consider talking to your doctor and getting your thyroid checked. Also, you should increase your calorie intake as Libby2999 pointed out. If you're burning 1000 a day and only eating 1000 - 1500, you're putting your body into starvation mode.'
While some people do okay on 1500 calorie a day diets, 1000 calories is below the minimum of 1200. So don't go below 1200.
Ultimately, you should be losing weight--even if you're cutting too much--unless there's something wrong.
Do your clothes feel any looser? Have you measured yourself or tried on a smaller size of clothing? Your scales may be inaccurate, or you may be losing slowly and not realizing it. Or there may be something else wrong.
Try increasing your calories. Your body might not want to lose anything cuz it feels deprived. Or possible you might be gaining muscle. Muscle weighs 3 times more than fat the same volume.