This was the first research project in the world to analyse children’s diets combined with both psychological and sociodemographic variables in the mother. As part of the Norwegian Mother and Child Cohort Study, a total of 27 763 mothers were asked how often and how much their 18 month old child ate of 36 types of food and drink. By this age, children learn to prefer sweet and fatty food over healthy food.
"We found that mothers who were emotionally unstable, anxious, angry, sad, had poor self-confidence or a negative view of the world were slightly more likely to give their child sweet and fatty foods. At the same time, there was no link between maternal personality and how healthy a diet the child got in the form of fruit and vegetables," explains psychologist Eivind Ystrøm at the NIPH.
These maternal personality traits fall under a collective name of high negative affectivity (negative emotions). These people often have a lower stress threshold, giving up quicker when faced with obstacles – e.g. in a disagreement – and often experience lack of control of the child.
"I think that mothers compensate for this either by trying to force healthy food into their child or hold the sweet-bag strings extra tightly. Paradoxically, they try to balance poor control by actually using more control. With force and restrictions they increase desire which quickly results in resistance in the form of tantrums which these mothers are also bad at resisting. Also, earlier studies have shown that controlling behaviour among parents is linked with a more sugar-rich diet among children."
Aid to nutritional advice
Ystrøm believes that knowledge about the link between the parents’ personality traits and children’s eating habits will be useful for health personnel and others who give nutritional advice.
"People with a lot of negative affectivity often express worry and appear to be helpless and insecure. Research into this type can help to create a toolbox of advice to relieve the feeling of stress and lack of coping and improve the child’s diet. Unfortunately we could not study the fathers, but it is likely that this also applies to them. Men with a lot of negative affectivity often express this in the form of anxiety or anger, but otherwise the characteristics are identical between the sexes."
Independent of sociodemographic factors
Research results were also controlled for the following sociodemographic factors; the child’s sex, smoking, child attending nursery, education, mother’s age, mother’s BMI, number of children, income and marital status. These data were collected from the Medical Birth Registry of Norway at the NIPH. None of them explained the effect that the mother’s negative affectivity had on the child’s diet.
"Or, to put it another way, the impact of sociodemographic variables on children’s eating habits was unaffected by the mother’s personality traits," says Ystrøm.
- Mothers who smoked daily, had a high BMI, had many children, had male child / children who went to nursery were less likely to give them a healthy diet.
- If the mothers were daily smokers, with a high BMI and/or many children, there was a greater chance that they would give their children an unhealthy diet.
- However, if mothers had a higher education and/or were older, they were more likely to give their children healthier food.
First study of 18 month old children’s nutritional patterns
As well as being the first study to compare a child’s diet with psychological and sociodemographic factors in the mother, this is also the first time that nutritional patterns in such young children are studied.
"This is important because we discovered that the same socioeconomic risk factors for sweet and fatty foods that were found earlier among three to six-year old children in England were already present at 18 months. In addition, this shows that parents’ ability to master stress can affect children’s eating habits from a very early age."
More about the method
Earlier studies indicate that anxiety and post-natal depression can affect a child’s eating habits. However, post-natal depression arises infrequently and usually abates during the first year, so it is probably irrelevant for the child’s eating habits over time. Therefore, with colleagues Susan Niegel and Margarete E. Vollrath, Ystrøm extended the research question to include the mother’s personality measured by negative affectivity.
Children’s eating habits were categorised as “healthy” and ”unhealthy”. Data were cross-checked with information about the mother’s demographic, medical and socioeconomic background from the Norwegian Institute of Public Health’s Medical Birth Registry. ”Healthy” and “unhealthy” foods were mutually uncorrelated for negative affectivity in the analysis, i.e. a child getting ice-cream for dessert would not affect the variable that the same child had sprouts for dinner.
Weaknesses of the study
The breadth and the number of indicators for the children’s eating habits were limited, as were the types of food that 18 month old children generally eat. Researchers only evaluated which foods children ate and not how they were served their food. Finally, a complete personality evaluation of the mothers could point to a more obvious and overall effect of their personality.
"Therefore, future studies should include all the five basic personality traits that are usually used in personality tests; extroversion, control, sociability and openness to new experiences, in addition to negative affectivity. It can also be interesting to look even closer at the process between a mother’s personality trait and the child’s diet that causes children of mothers with high negative affectivity to have a poor diet," says Ystrøm.
In an earlier study, Ystrøm and his colleagues highlighted that mothers with a high level of negative affectivity often cease breastfeeding before the recommended six month limit.
Reference: Ystrøm E, Niegel S, Vollrath ME. The impact of maternal negative affectivity on dietary patterns of 18-month-old children in the Norwegian mother and child cohort study: Maternal & Child Nutrition 2009.