Obesity isn’t only a burden for physical health, but it spells trouble for the mind too — as early as first grade. A new study finds that severely obese children have an increased risk of being ostracized by and isolated from fellow peers, and suffer from depression, within their first years in school. While we may have all experienced body shaming in school — or taken part in it — the results lend more weight to the consequences of obesity.

“Severe obesity is a clear psychosocial risk for children, even as early as 6 years old,” said Amanda Harrist, professor of child development at Oklahoma State University and an author of the study, in a press release. “Children who are ostracized, as occurred with the severely overweight children in our study, suffer great harm, with feelings of loneliness, depression, and aggression, and these children are more likely to skip school and drop out later.”

Examining 1,164 first graders from 29 rural schools in Oklahoma, the researchers focused on the emotional and social health of obese children. The children lived in 20 different towns throughout eight counties with adult obesity rates as high as 28 to 41 percent, and most of them came from low-income, white backgrounds.

As a child’s obesity level increased, their social and emotional health worsened, the study found. Children in general, including non-obese kids, rarely mentioned obese children as being a favorite classmate or playmate compared to non-obese kids. In addition, severely obese children were more likely to be teased or ostracized and to show symptoms of depression. Those who were severely obese had it worse than those who were simply overweight.

Understanding the emotional and social effects of obesity is important, because it plays a huge role in weight management, body image, and overall health later on. Getting rejected by schoolmates may only contribute to the vicious cycle of obesity and emotional eating, as well as low self-esteem, that prevents people from losing weight.

Earlier this year, the World Health Organization stated that the amount of obese and overweight children under the age of 5 was “alarming,” with the number as high as 41 million around the globe. The social and emotional issues among obese kids that begin as early as first grade only lead to worse problems down the road, including a greater risk of mental health issues, as well as lost productivity at work and even lower work wages among obese people, according to the Harvard T.H. Chan School of Public Health.

The researchers believe that treatment and prevention can start just as early as the bullying does. This may, in turn, prevent the mental health consequences of poor relationships and low self-esteem later on, and perhaps boost children’s ability to live healthier lives.

“Intervention or prevention efforts should begin early and target peer relationships,” said Glade Topham, associate professor of marriage and family therapy at Oklahoma State University and an author of the study, in the press release. “Interventions addressing the behavior of peer groups can limit exclusion and teasing, and help students form friendships.”

Source: Harrist A, Topham G, et al. Child Development. 2016.