If an eating disorder is about eating too much, then that can be because of eating the wrong foods that are not giving the body the proper nutrition it needs, which can be different for each person. If the disorder is because of simply not eating the right foods, same thing, can mean the body is not getting the proper nutrition it needs, so the desire is to eat more.
Either way, I'd recommend seeing a Dietician.
I think today folks eat too much processed foods, sweets, cakes, cookies, sodas, basically a lot of sugar. Refined sugar is not natural. We get natural sugars from fruit.