a calorie is not a calorie. dropping 180 calories per day of other stuff (protein for example) isn't as effective for weight loss as something as high on the insulin index as white bread. You managed your body's response to food and that is what made the difference.
I could eat 2000 cals a day and maintain my weight. I can also eat 4000 cals a day and maintain my weight - the difference is in WHICH foods I use to maintain. Once you figure that out you're golden.