Poor body image in children as young as eight could be linked with hormone levels associated with the onset of puberty, Melbourne researchers believe.

Key points: The study of 1,100 boys and girls found a link between hormone levels and body image

The study of 1,100 boys and girls found a link between hormone levels and body image The higher the level of hormones, the more unhappy the children were about their appearance

The higher the level of hormones, the more unhappy the children were about their appearance One third of the children were dissatisfied with their bodies

A study conducted by the Murdoch Children's Research Institute and the University of Melbourne involving 1,100 girls and boys aged eight and nine found one third were unhappy with their bodies.

Girls tended to be more dissatisfied with their bodies than boys, but boys with higher hormone levels also felt unhappy with their physical shape, lead author Libby Hughes said.

"Basically the higher the level of hormones, the more unhappy the children were with their body size," Dr Hughes said.

"However children with heightened levels of hormones also tend to be taller and heavier than their peers, and this could be the cause of their poor body image."

"It's hard to know at this point what the direct effect is, whether there is a direct influence of hormones on how children are feeling about their bodies, or whether it is a chain reaction effect that hormones are impacting on how children look."

Children were asked to select the silhouette that best represented them. ( ABC News )

It was the first time the link between hormones and body satisfaction in young children has been studied, researchers said.

The Butterfly Foundation, which researches eating disorders and provides support for those affected by the illness, said body image problems did not discriminate and people of every age were at risk.

"Poor body image can contribute to impaired mental and physical health, lower social functionality and poor lifestyle choices," said spokeswoman Kim Borrowdale.

"Body dissatisfaction, the experience of feelings of shame, sadness or anger associated with the body, can lead to extreme weight control behaviours and is a leading risk factor for the development of eating disorders."

The study used eight illustrated silhouettes of children ranging from very thin to very obese to measure the children's dissatisfaction.

Each child was asked to select the one that looked most like them, and then select the one they wanted to look like.

Researchers subtracted the two choices to come up with either a negative or positive body satisfaction score.

'I feel like everyone around me is quite thin'

Riley Collins, 14, participated in the study as an eight-year-old, and repeated the exercise today.

"I've drawn myself as a five, and probably wanted to look more like a four, just because I feel like everyone around me is quite thin," he said.

Riley Collins said he would like to be thinner. ( ABC News )

His mother, Julia Fahey, said she was surprised to hear her son express concerns about his body.

"I always looked at Riley as a kid who really didn't have any problems, that he was growing normally, a good size, a good height," she said.

Another participant in the study, Anika Floris, said social media had a big impact on how young people thought about their bodies.

"In this day and age it is really hard to not want to change some aspect of yourself," she said.

"People portray this perfect life — they only post what they want you to see — and then you're like 'I look like this and they look like that, so maybe that's what I need to look like as well.'"

Anika's mother, Kelly Floris, said the study had prompted her to talk to all of her children about body image.

"I am well aware that social media's had a huge impact on our children," she said.

"As a mother of girls, and of a boy as well, but particularly the girls, try to make it about health, and about what they're eating, rather than the calorie intake."

Anika Floris said social media had made her worry about her body image. ( ABC News )

The fact that more children are going through puberty earlier means self-esteem programs needed to be delivered at a much earlier age, before puberty, Dr Hughes said.

Parents needed to be good role models in the way they talked about their own bodies and other people's bodies, she said.

It was also important to talk about what bodies do, rather than how they look.

"There may be a need for community and school programs that help young people learn about what underpins good self-esteem, because self-esteem is not solely invested in physical appearance," Dr Hughes said.