I'm a bulimic in recovery.
I was bulimic for 15 years and now in recovery for 20 years (with one relapse 10 years ago when my father died. Stress tends to bring it out).
Prince Charles could not 'cause' bulimia with one remark. It's impossible. I'm sure that Diana did say he did and probably even thought he did when he said it. When I was bulimic I used to go round and round in circles in my head and think of different reasons why I was 'like that' and why I couldn't stop. (I desperately wanted to stop and could not). I used to find other people to blame, especially those closest to me.
Diana had a lot of traits typical of bulimics. A typical bulimic is a woman and it usually starts at a young age, during the teenage years. She is a perfectionist and anxious to please and very hard on herself more than anyone else is. She doesn't 'see' herself properly. She may look very beautiful to everyone else but when she looks in a mirror she honestly does not see what she looks like--she sees a lot of (often imaginary) imperfections and flaws. She never really believes she looks right or has done things so constantly needs someone outside of herself to keep repeating that she looks 'okay' and has not done anything embarrassing or wrong. It's never enough--it's a bottomless pit. If she goes out and 99% of the people she meets say she looks great but 1% does not comment--I don't mean that 1% insults her or anything like that but just does not comment--then she decides that she looks horrible and is disgusting and goes into self-loathing that is difficult for normal people to understand or believe. It's like there is nothing inside and she has to keep being fed encouragement all the time.
It's unbelievably exhausting for those who are near and dear. She has to have a lot of control over the environment and circumstances. The perfectionism is extreme. So is the black and white thinking--i.e. everything that isn't wonderful is awful.
I can definitely see a bulimic young girl of 19 marrying into the royal family, not so much to Charles personally as into the royal family, because of the feeling that that would make life 'perfect' and that she would finally be happy and feel loved. Caught up in a dream more than most girls would be. And then the feeling of betrayal once any little wrong thing came out--and the exagerration of it in her own mind and the overdramatic and theatrical reactions. The reactions would seem overdramatic to other people--but she would not realize that they were. Reacting more to what is going on in her head than to what had actually been said or done. When I was actively bulimic, my husband was walking on eggs. He couldn't say anything that I didn't take offense to and wasn't very drastic about, but anything that seemed even a little like criticism joined the chorus in my head saying that I was awful and I would horribly overreact (and really be devastated, it wasn't pretending).
Bulimia is not really about the food. The bulimic will eat gigantic amounts because it is a soothing thing. Think of how soporific and calm you feel after you overeat at Christmas or thanksgiving dinner. That is the effect they are seeking. But then they will be horrified that they ate so much and fear the weight gain, because they would rather be dead than not considered to be perfect and beautiful by others. so then the purging. The purging does not have to be vomiting. some bulimics compulsively exercise. I suspect that the way Diana got into exercise eventually may have been part of the manifestations of the disease. Also, the things she did such as colon cleansing and so forth. Many bulimics use laxatives to purge and this would just be a step further on.
People confuse bulimia with anorexia, and some people have a mixure of eating disorders but they are generally quite different diseases. Bulimics are not, generally, extraordinarily thin. You do get the bad skin and the tooth enamel problems--but as stated above, that takes a long time. Bulimics are the 'perfect' women you see who seem to have it all together. They are not necessarily born beauties, like Diana, but they are the ones whose weight is perfect, who have lovely figures from exercising, whose makeup and hair is always perfect, whose outfits always are striking and catch attention. (they have to have attention, because as I said before, there's nothing inside). Unless you are living with them, you do not realize how volatile they are and how easily upset and what mood swings they have. To the outside, the bulimic person looks like perfection and like the husband is lucky to have such a perfect wife who grooms and cares and for herself so well, keeps the home so well and is such a perfect mother, etc. and no one sees the inside where she is (not deliberately, it's really sad) draining everyone around her dry. Including the children whom she really does love. A bulimics children learn early that mommy is fragile and that it is their job to build her up and take care of her and makes sure she feels okay (which she never does) and because she does not she seeks the opportunities where she looks good to others to get the compliments that she hopes will help. That would explain a lot of Diana's charity work. She needed it--especially probably in the middle of the night. A sick person thinking she was wonderful would make her feel okay--temporarily. The insatiable need to be complimented can't be fulfilled by the family.
There is a genetic component definitely. Bulimics tend to come from families where there are problems such as alcoholism, where there is a lot of obsessive compulsivenss and the disease does come along with depression and clinical anxiety. The food can mask the other problems. Only when I got into a program and worked on my bulimia did I realize that I had depression and anxiety. Once the food was gone, because it acts as self-medication, the other problems became obvious and I had to get help for those.
Diana was in a situation, with all the fame and publicity, where it would have been hard for her to get proper treatment and also where she could easily get her 'drug' --not food, but the constant attention and ego stroking. It would seem like a dream come true for most bulimics to be assured by every newspaper in the world every day that they were one of the world's most beautiful women and one of the most well-dressed. AS well as one of the kindest and most compassionate, etc. etc. They would not really believe it inside, but they could keep looking at the newspapers and avoid the problem.
She was exactly where she was least likely to get real help and where she could keep her disease active. She was also very young when she died. When I was 37 I had learned to deal with some things but not with most things yet. I do a little better now--but I'm 55 and have been in a program for 25 years.
It also would be very bad for a bulimic to be in a situation where another woman was continually being preferred to them and where they could feel even more unloved and unworthy. the Camilla situation would hit diana harder than most people. It's all very sad and especially that she died when she was in a period of great stress--one year divorced, father recently dead, etc. etc. There was a lot of good there although she did do some really appalling things and I think with maturity and treatment she would have been quite different now, at age 50.
The other thing that's sad is that it's so hard for someone with so much celebrity to get real treatment. Charles behaved horribly in marrying a young girl, any young girl and then having an extra-marital affair but to be honest I do think the bulimia was more than he could deal with. It's very hard. I'm lucky that my husband is truly in love with me and has been endlessly patient to learn about this disease and be endlessly supportive and reassuring and has helped me get help and also helped me. But it's a lot to do and I don't think someone that didn't really love someone would stick in there. If your wife has something like cancer or has lost a leg, everyone sees you have a lot to do and admires you for all the care you take of her and knows what you are going through. But with the bulimic, she looks so perfect on the outside and everyone thinks how lucky you are. And they don't know know what you go through at home and how difficult it can be. One thing my husband does for me now is to help me to notice when the crazy thinking is coming on and then encourages me to go to the meetings that help. but if we were in the royal family we'd have no privacy and no resources for him to do that.