Why do people assume parents on diets and self-conscious about weight give their kids eating disorders?
Mostly, it seems to be a very unsophisticated view of mental illness. People confuse disordered eating (a behavior, and all too common), with an eating disorder (the very-poorly conceived name for a brain disorder with symptoms and perpetuating factors around eating). This is similar to believing eating a lot of sugar leads to Type I Diabetes. Or eating eggs will make you fertile.
Reframe: the symptoms of self-consciousness, body image distress, drive to avoid food can all happen without outside influences at all. The brain can be wired that way, or wired to think that way when precipitated by energy imbalance. Often, the environment DOES send all these messages, and even in healthy people they have an effect, but not to the hallucinatory and rigid way seen with eating disorders.
WIthout the genetics and predisposition our kids could, as many do, try on all sorts of disordered behaviors but they won't be able to sustain them. They may believe all sorts of wacky ideas about food and weight but logic and persuasion still work for them. In other words, we're talking about a genuine mind-altering brain disorder and not a set of bad choices.
So it can be true that a mother was on a diet and the daughter developed an eating disorder, of course. It did in our family: I'd been fighting the spread of middle age just as my doctor and media and friends told me I should: eating less, eating different things, choosing different activities. When my daughter developed extreme versions of those same thoughts and behaviors it seemed obvious where they came from. I wasted precious time backpedalling and trying to get her to be only as disordered as me, which at the time I referred to as "balanced." Now I realize my dieting was stupid and unhealthy but I also know it no more made my daughter mentally ill than it made me fit into my high school jeans. (a cheap knock off of the designer jeans I really wanted my mom to buy)
I did disordered eating, but I didn't have an eating disorder. I was just a fool. My daughter was not.
I now know that it is more like Obsessive Compulsive Disorder. You can't catch it or be pushed into it. A mother who keeps a clean house doesn't push her children to develop compulsive hand washing. Can you imagine demonizing that mother as "setting unrealistic standards of cleanliness?"