A big British modelling agency has agreed to stop using models who are too skinny.
Elite Model Management has backed a campaign, started by fashion magazine Vogue, to promote healthier views of body image among children.
They say they won't knowingly use any models who are under 16 or who look like they could have an eating disorder.
The fashion world has been criticised for using models who are really thin.
Some people think this could cause eating disorders among girls who see the pictures and try to copy them.
What do you think of models in magazines and adverts? Are they too skinny or do you think magazines get it right? Do you reckon they should avoid skinny models or do you think it doesn't matters who they use?
Here are some of the comments you sent in.
"I'm glad they've banned young models and ones that are too thin because I think they're a bad influence on vulnerable girls who might start dieting when they are actually a healthy weight. The only thing the skinny models do is promote anorexia. People should put their health first not their size and shape."
Rebecca, Manchester, England
"Models are way too skinny not only on magazines but everywhere like on TV and in books. It makes people in my class who aren't so skinny jealous."
Lucy, London, England
"Yes, there are too many skinny models. I wonder what people would say if overweight or average models went up there for a change..."
"I don't think skinny models should be banned if they have a good diet but if they don't eat much then they should be banned."
Amy, London, England
"I think it's really unfair because it influences girls and makes them not happy about their bodies."
Mieke, Ipswich, England
"My friend has anorexia, a severe eating disorder, and I hate seeing tiny models in magazines encouraging this..."
Rachel, Warrington, England
"No, because it is the models choice to be skinny or not."
Ali, London, England
"Models are too skinny but I think the biggest problem is the editing of the images after. If someone is having a bad day, seeing one of these 'perfect' people can really bring them down."
"It would be nice to see normal people modelling clothes as they will be the people wearing them. It's not healthy for the models or for the teenagers and children who copy them!"
Sophie, Somerset, England
"I think they are way to skinny. People say looks are not everything so why are there so many skinny models? They should have models of all sizes and shapes."
Bethany, Greater London, England
"Yes, models are very skinny. They are a bad role model for children and they can cause eating disorders in children."
Lauren, London, England
"I think they should be banned as it makes people like me feel fat. Many girls in my class think their body isn't right and it makes a lot of us not want to eat and we feel we aren't pretty."
Nicola, Leeds, England
"I think stick-thin models are unhealthy and no model should become stick-thin just to keep their job."
"I think they are way too skinny and why should people size 14 be called plus size? They are normal models!"
"I think it's right that they have been banned, because any teenager might want to be a model and they think they have to be super skinny. They might get an eating disorder or something trying to look like that."
Ebony, Essex, England
"I think the problem is not only in magazines but in TV as well. Female characters in Disney shows are always really skinny and something should change."
Annie, Manchester, England
"I think that most models are way too skinny! It looks creepy - and it influences my friends to become as skinny as them. I hate it!"
Maddy, Cheltenham, England
"I think its disgusting how skinny some models are and it sets a bad impression for kids and teens because we feel we have to reach their standard. I think they should have larger people in magazines as well as slim ones to show that everyone is beautiful and you don't have to be stick thin to be pretty."
Katie, Lincolnshire, England
"I think they should only use healthy bodies no question about it."
Daisy, Norfolk, England
"Yes I do think models are too skinny and it is making kids and teenagers paranoid about their figures."
Yana, Gloucestershire, England