Kids as young as three are fat-phobic, which means larger children are being shunned, a La Trobe University study has found.
The study found that three to five-year-olds don't want to invite their larger-sized peers to birthday parties, News.com.au reported.
They think fatter children won't have many friends and are meaner, sadder and lazier than skinnier kids.
The study, of 118 Victorian preschoolers, is one of the first to reveal anti-fat attitudes in children this young.
Across all genders and ages, the children studied chose larger figures as having negative rather than positive characteristics.
Experts said that it illustrates the growing discrimination against larger-sized children, who make up one in four Australian kids.
Victorian Equal Opportunity and Human Rights Commission figures show 94 people made formal discrimination complaints based on physical size in the past five years.
This included children bullied at school by peers or denied the chance to join sporting teams because of their weight.
Acting EO Commissioner Karen Toohey has urged parents to help combat size discrimination against children.
"Whether it's preschool or school, we have to make sure there is a safe environment for all kids," she said.
Toohey said parents were mostly to blame for passing poor attitudes on to their kids.
La Trobe University researcher Emma Spiel said the research showed "negative weight attitudes were present very early in life."
"Such attitudes are likely to pave the way for the negative appearance comments and teasing of overweight peers," she said.
The study is published in the Body Image journal. (ANI)