We know that weight stigma — both overt and hidden — can be disastrous for our mental and physical health. But what's especially jarring about a new study on the subject is that it shows just how early in our lives those effects begin to appear. For the study, published online this week in Child Development, researchers recruited 1,164 first-grade kids (via their parents) from 29 rural Oklahoma schools. They analyzed reports of the first-graders' popularity from their teachers, their classmates, and from the kids themselves. The researchers also took note of the students' BMI measurements and gave them a questionnaire designed to measure signs of depression. Results showed that the higher the students' BMIs were, the more likely they were to be neglected and even rejected by their peers. That means that fewer of their peers were likely to say they wanted to play with them and they were often mentioned as the "least favorite" classmate. Alongside the classroom dynamics, those students with higher BMIs also showed early signs of depression, including low self-esteem. "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," the study's first author, Amanda W. Harrist, PhD, said in a press release. These findings mirror those found later in life: Adults who have experienced more weight stigma in their lives are also more likely to develop depression. As we know from other research on adults, attempting to shame people for their weight doesn't help them lose weight, and may instead do some very real harm in terms of physical and mental health. Similarly, the authors of this study argue that facing this stigma early on may kickstart a lifelong struggle with body image.