Offering a preschooler a hug rather than a lolly when upset will help ensure they don't become emotional eaters later in life, say Norwegian psychologists.

Emotional eaters can blame the unhealthy habit on their parents, according to new Scandinavian research.

A six-year longitudinal study from Norway, published in journal Child Development, has found that school-age children whose parents fed them more to soothe their negative feelings were more likely to eat emotionally later on.

The reverse was also found to be the case.

"Understanding where emotional eating comes from is important because such behaviour can increase the risk for being overweight and developing eating disorders," said the study's lead author, Silje Steinsbekk, associate professor of psychology at the Norwegian University of Science and Technology.

When children eat to soothe their negative feelings, the evidence shows the food tends to be high in calories so they consume more calories, and if they emotionally overeat often, they are also more likely to be overweight.

Emotional eating is also tied to the development of later eating disorders such as bulimia and binge eating.

"If we can find out what influences the development of emotional eating in young children, parents can be given helpful advice about how to prevent it," Prof Steinsbekk said.

Researchers at the Norwegian University of Science and Technology examined a group of 801 Norwegian four-year-olds, looking at them again at ages 6, 8, and 10.

Their parents were also asked to complete questionnaires describing their children's emotional eating and temperament, as well as their own emotional feeding.

Approximately 65 per cent of the children displayed some emotional eating. Only 35 per cent were reported to have "never" displayed emotional eating.

The study found that young children whose parents offered them food for comfort at ages four and six had more emotional eating at ages eight and 10.

While the level of emotional feeding reported was low, even low levels increased the likelihood of children regulating their emotions with food.

"This study adds to existing research and suggests emotional feeding prospectively predicts emotional eating in middle childhood," the authors wrote.

Higher levels of negative emotions, such as anger and crying at age four also increased children's risk for emotional eating at age six.

Offering a child a hug rather than a lolly when they are upset is a better option, suggested the authors.

"Food may work to calm a child, but the downside is teaching children to rely on food to deal with negative emotions, which can have negative consequences in the long run," said Prof Steinsbekk.