Which charity should I choose to help for growing anorexia and unhealthy eating?!

I am looking to help fund raise for a charity, to promote awareness of how much teenagers and young adults of our time have been brain washed into being skinny size 0 to 6 in order to be considered beautiful in the society. I have some friends who have been affected by the media and the fashion world into believing that 'skinny' is beautiful, and it hurts me to see them damaging themselves.
Does anyone know of a trustworthy charity or organisation which this cause would be related to?

Many thanks