That's the frustrating part really. In her mind, she really feels that she's telling the truth, but the truth is that she is so detached from reality that she doesn't know how little 400 - 800 calories is. I've watched a few episodes of Secret Eaters, and the common point is that all the fats think they eat at most 2000 calories a day. Why? Because they have all heard that a normal amount is about 2000 calories, and since they think they eat like a normal person, their calorie intake is 2000. But, they have never counted calories once in their life, hence the delusion.