Not eating enough? Weight loss indicator?

did you try adding a couple of snacks during the day?? Like a yogurt??

In my past I have been told that I don't eat enough for my body weight and the amount of calories I burn. My goal is to see a "1" as the first number on the scale which I have never seen. I am 51 years old, used to be 250 pounds overweight...long story short, when I exercise I cannot find the way to eat the calories suggested and am not losing weight in conjunction with my calorie burn which is usually 500 cal plus/minus every day of the week. Does anyone have experience or advice regarding eating the target calories? I have added protein rather than FAT OR CARBS but still I wonder if eating the high end of my range is suggested. Yikes, anyone?