Urgh this is really grim. I know how she felt I hate being a big bird! :sigh:
However 530 calories a day is insane! I love my food and I could never do a diet like that, I would go nuts! hehe. The problem with these very low calorie types of diet is they can cause your body to eat away at muscle so this diet could have been affecting her heart. I tried to do a 1200 calorie diet at 18 stone ish and I got told off by my Doctor who said it was way too drastic seeing as my body was used to 2300+ calories a day. She sent me to a nutritionist who would reduce my calorie intake a little a month so I could adjust and my body would be ok. I lost 3 stone this way! But then I fell in love and ate takeaway and watched films, damnit! ha.
I know a lot of people, especially the media, love saying how bad certain diets are. So I don't really think people should blame the diet seeing as it works for thousands of people. For example I am on an Atkins type diet and people always say 'how can eating fat make you lose weight and be healthy'. It gets really annoying after a while!