I'm not surprised. Wonder why Atkins is working well for me, tho. I'm eating more, and losing weight. I still think what you eat has an impact. Not all calories are exactly equal, but I'm gathering overall it usually comes down to burning more than you take in.
This is why Atkins works. (mild warning, old B&W clinical/medical photos of a boy in a loincloth)
http://www.wellesley.edu/Chemistry/Chem101/hormones/diabetic.jpgThis is a before and after pic of a boy who was lucky enough to survive to the 1920s when Horse Insulin became available. The human body simply can't deposit fat stores from protiens and low-carb green vegetables alone. To prevent diabetic coma and death, diabetes sufferers would eat virtually no carbohydrates, yet they'd starve to death. Before Insulin, it was just prolonging the inevitable.
This is why on Atkins you can eat as much protein, fat, and low carb vegetable matter to fill your stomach and quell any hunger pangs you want, and you won't gain weight. No amount of calories that don't include carbs will let you gain weight in the long run. Either because you can't process them due to being unable to produce insulin, or simply refusing to eat them.
So, "calories are calories" isn't completely true.
