Well, that's actually a very simple question to answer. And no, it is not society, it's not skinny models or social pressure.
And then again - those things can all be the trigger that offsets the gun aka the underlying disposition.
Still, if you are not biochemically wired to be vulnerable to using and abusing food and starvation, you will never turn to food as your method of coping with life. You might instead turn to dopamine enhancing behaviors - i.e. certain drugs, smoking (both serotonin and dopamine inducing), excessive shopping, sex addiction or even kleptomania.
Women actually have only 52% serotonin of that of men.
This means women are super vulnerable to anything that depletes serotonin - we don't have a buffer, so to say.
Serotonin is easily to influence through food and starvation.
So when we mess with either aspects of these, we walk a fine line towards caving in to a biological vulnerability that will "support" an eating disorder. Why most stories of an eating disorder starts with going on a diet. Most diets are geared around restricting one macronutrient group or the other. This is greatly appealing to our magic pill mindset: that if only we cut out one thing, then everything else will magically change.
We love magic pills, and that's why there's a new diet book with every changing of the season.
What does this mean in practicality? It means, women do not thrive on the same food habits as that of men. We are biochemically different - that really shouldn't come as much of a surprise: Men are different from women. And yes, that means each gender thrive on specific lifestyle and food strategies. When we go against the laws of nature - we get sick. Or we struggle, we get depressed, we experience chronic hunger and temper tantrums all the while we are sticking some diet that we think is good for us, but in fact, it is not. If it doesn't make life feel effortless and us happy, it is not a good diet we have chosen. End of story.
Yes, change is always hard to a certain extent.
And changing food habits if we've been living off MacD is not easy, that's not what I am saying here. What I am saying is, that I see far too many of us who are busy counting, cutting out and eating things while we are feeling incredibly lethargic and moody. A steady production of serotonin requires a balanced intake of protein, carbs and fat. it is actually very easy to do, but with the dieting trend always cutting out of one these groups depending on what's in style, more and more of us are suffering from serotonin related issued based on our dieting behaviours.
Balance - as much as we kinda find that word a bit boring, is that name of the game.
And think about it, hey, isn't it more boring to exchange your super tasty whole-grain spelt burger bun for a salad leaf? Or making spaghetti out of squash? Or making pretend meat out of mushrooms and beans. Super boring.