I am not fat or anything (5'9" 160lbs). I did atkins diet for 4 weeks just for testing. It works pretty good. But you have to really watch how much carbs you are taking. To do that you have to measure your ketone release (with urine). Ketone is a by product when your body burns fat for energy. There are lot of over the counter ketone measurement strips costs around $12 for 50 strips.
But you must take good amount of vegis and multi-vitamins. It is quite hard to adjust in first few weeks, as we are "bhate bangali".