Actually, she doesn't eat breakfast, lunch or snacks during the day.
She starts eating at 6pm, pigging out and I assume she eats dinner. But eventually she goes to sleep. She isn't actually eating all day. So yes she can maintain her weight if she purges once a week (perhaps on the day she eats the most, who knows).
I have never purged, but I definitely know this eating pattern. And you can maintain your weight this way. Of course, it's a horrible thing to do. I've eaten this way many times, not exactly pigging out in the evening, but not eating all day and then eating two meals worth of calories at night. I don't have a body image problem, I'm just so very not hungry during the day. But I try.
Yep, I missed the part about eating after 6 pm. Still, you can pack in a lot of calories before you go to bed.
Amazed that anyone could eat this way - keep their energy level up - keep a job - or function during the day.
Frankly, I'd collapse about 3PM if hadn't eaten lunch and breakfast.