What is the main source of Simone's negative body image?

Though Simone does report feeling overwhelmed when she looks at the perfection on display in fashion magazines, she tells Amal that the main source of her insecurity stems from her mother's treatment. Simone's mother tells her that she is never going to find a man to love her if she does not lose weight and she often tells Simone that when she was Simone's age, she was a size six.