Obesity and cognitive problems and sleep-disordered breathing (SDB) have been shown to have a causative relationship in young children.
Doctors at the University of Chicago found that youngsters who have one of the conditions are more likely to suffer from the other ailments.
"The intricate interdependencies between body mass index, SDB and cognition shown in our study are of particular importance in children, as their brains are still rapidly developing," said the study's author Karen Spruyt, assistant professor in the Department of Paediatrics at the Pritzer School of Medicine.
She now believes that losing weight can have significant benefits to a child's educational development.
The research examined more than 351 school children with an average age of 7.9.
According to the latest statistics from the Department of Health, more than one in ten children aged between two and ten are overweight and if current rates continue 35 per cent will be obese by 2050.