I think what someone realy needs to point out here that anorexic/bulimic does not mean skinny. Those things are psychological disorders, they have nothing to do with weight directly. Many anorexics and even more bulimics are of normal weight and some are even overweight.
The problem with both disorders, which normally occur simultaneously, is that the victim normally runs through stages of binging followed by periods of purging, over exercising and fasting. As a result an anorexic can in theory get far more calories than a ‘normal’ person and can readily have the same calorie intake.
Just because one of these girls was diagnosed an anorexic does not men she has to be underweight at all. Normally anorexia is a degenerative disease that will lead to dangerous weight loss and normally that is when it is detected, but not always. Ironically a person can be a full-blown anorexic and actually be overweight.