A VOLUNTARY code of conduct requiring the media and fashion industries to use "normal-sized" models and identify manipulated images will not lead to fewer stick-thin models in magazines and on catwalks, industry insiders and health experts say.

The Minister for Youth, Kate Ellis, yesterday announced a $125,000 plan to develop national guidelines on body image to tackle the "silent epidemic" of eating disorders plaguing teenagers and young women.

These could include an age limit of 16 for catwalk or advertising models, a commitment to using models of varied colours, sizes and shapes, and tagging digitally enhanced images.

Ms Ellis said it would be up to individual media outlets, advertisers, modelling agencies and fashion designers to abide by the code. A voluntary code introduced by the Victorian Government last year had gained broad support.

Flinders University law professor Elizabeth Handsley said such codes tended to be nothing more than a "PR exercise".

The Government will appoint a national advisory group of media, fashion, health, education and advertising representatives to develop guidelines next year.

Mia Freedman, a former editor of Dolly, Cosmopolitan and Cleo , said no fashion magazine editors would abide by the code because they argue they are selling "fantasy" not "reality".

Sales and advertising revenue increased when she ordered the use of average-size models in Cosmo but no rivals followed suit. "It's hard to find the right models, it's hard to convince the photographers to shoot them and it's hard to find the clothes to put them in, so why would you do it?"

One in 100 adolescent girls develops anorexia, the obsessive refusal to eat, and five in 100 develop bulimia, typically later.