Children labelled as being too heavy by their parents went on to weigh more as adults than children of similar weight whose parents did not label them as fat.
Singling out children for their puppy fat can leave them 'psychologically scarred' and likely to get even fatter in future, a study has found.
So-called 'fat shaming' may lead to feelings of stigma that result in comfort eating, researchers say.
Being told they were overweight also led the children to make ultimately unsuccessful attempts to diet.
The findings may cost doubt on the wisdom of the nationwide NHS scheme to measure the height and weight of all primary school children, in which many pupils have been labelled as overweight or obese.
Nutella for breakfast not ideal. PICTURE: Instagram Eric Robinson of Liverpool University and Angelina Sutin of Florida State University analysed two large studies which track child development.
In the first study, the Longitudinal Study of Australian Children, tracked the weight of children in 4,983 families from the ages of four or five until 14 or 15 years old.
READ:Why I will allow my kids to struggle in 2017
During the course of the study, parents were asked if they considered their children to be either underweight, normal weight, somewhat overweight and very overweight.
The authors write 'children who were perceived as being overweight at age 4 or 5 gained more weight over the next decade, in part because they perceived themselves to be overweight.'
The children also 'made more attempts to lose weight through dieting at age 12 or 13 than the children who were perceived as normal weight earlier in childhood.'
One in five children in the study were overweight or obese although 86 per cent of their parents thought they were 'normal'.
In the second study of 8,568 families the Growing Up in Ireland study followed children at two points in their lives at the ages of nine and 13.
At both ages, parents were interviewed and similarly asked if they considered their child to be underweight, overweight or normal.
The authors said the second study found the same result as that in Australia.
Compared with children whose parents perceived them to be of normal weight, the children seen as overweight at age nine 'gained more weight by age 13'.
Just as in the first study, the children labelled as overweight had also made more attempts to diet.
Watermelon break. PICTURE: Instagram Many of the parents did not see their children as overweight even though the body mass index of a third of the children showed they were overweight or obese
Of these overweight children, more than half, 55% were identified as being of normal weight by their parent, while 44 per cent were accurately seen as overweight.
READ: What happens when a narcissist becomes a parent
In both studies, the authors controlled for factors such as parents suffering from depression and being overweight and obese themselves.
In conclusion the authors write: 'Across two studies, we replicated the finding that children whose parents perceive them to be overweight are likely to gain more weight than peers who parents do not consider them to be overweight.'