Audrae, Many pasta's are made from refined flour - which has a high glycemic index, meaning that your body can convert it rapidly to calories and then fat (Fat doesn't necessarily make you fat, excess calories do - fat just has more calories per unit than carbs or protein). There are some pastas with other grains in them that are a better for you but the whole wheat ones are not very good IMO. A serving size of pasta is much smaller than what most people put on their plate. Moderation and a balanced diet is what the girl should be striving for.

Also pasta expands when it hits your stomach. Making you feel fuller sooner. That's why they say only eat so much of it. Once you expand your stomach it's harder to get it to go back back down. I only eat enough to make me feel comfortable and i'm done.

You also might want to talk to your daughter about anorexia and inform her that the brain needs a proper amount of fat in one's diet in order to function. Clearly she isn't getting enough fat for her brain if she thinks pasta is "fattening." Just don't eat a huge bowl of it alone as a meal, and don't cover it in alfredo sauce. Make sure you are pairing it with protein and vegtables.