Should Designer Use Models That Are Too Thin?

http://www.dailymail.co.uk/femail/article-1359713/London-Fashion-Week-2011-Skeletal-models-super-sized-hypocrisy.html

After careful thought I have decided to research more into this subject as I feel that this is a debate that everyone should be able to comment on. Not only does the catwalk still promote unhealthy looking models but I wonder what affect this has on young women/men who look to this profession as "role models". Should are role models be of a certain size? Should they look healthy? Can this kind of marketing be a catalyst for eating disorders in young people? I want to find out.