You need to eat more calories. 1000 is not enough, and therefore, your body thinks it is starving, and holds on to every precious little bit. You should aim for about 1500 and your body will most likely start dropping pounds. Also, are you exercising? In order to lose weight, you need to burn more than you take in, and exercise will raise your metabolism to help you burn more.
If you are always hungry, try eating small meals every three hours instead of breakfast, lunch, and dinner. Long periods between eating can cause insulin spike, which makes you crave foods and feel starved. For example try:
Breakfast:
English muffin w/tsp of light butter
Mid-morning:
Fat free yogurt
Lunch:
Chicken breast with steamed vegetables
sugar free jello or pudding cup
Mid-afternoon:
Banana or apple
Dinner:
whole wheat pasta with homemade tomato sauce (canned sauce from store with your own spices, much healthier than the stuff in jars)
slice of italian bread with tsp. light margarine
salad with lite italian dressing
sugar-free jello
You'll feel more satisfied, and less inclined to binge on naughty foods, because you won't be starving.