@umbra21 - I think that was the popular treatment for people with eating disorders for a while. They had to address their physical symptoms before going on to the emotional ones.
I hope your friend was all right in the end. I'm sure they would have kept an eye on her hypokalemia if they knew she could be in danger.
Bananas are often recommended for people suffering from this deficiency, but diabetics should, of course, make sure that they aren't going to upset their blood sugar before eating them.
I think beans are actually a better all around choice, just because they are often easier to slip into normal meals.