Written by Constantine Gasser | PhD Student in Community Health Services Research at Murdoch Children's Research Institute

In the lead up to Christmas, with the added availability of many other calorie-rich foods such as fruit-mince tarts, chocolates and Christmas hams in supermarkets, we can be tempted to abandon our normally healthy diets. With school holidays and the festive season fast approaching, it is important that we think about the dangers of unhealthy foods. When you walk into a supermarket, you usually find a myriad of junk foods - soft drinks, chocolates and chips – at the checkouts, and often at the front and back of aisles. These foods are usually marked at substantially reduced prices, sometimes half price, and are often available in bulk packages. 

The vast array of unhealthy foods in supermarkets is particularly problematic because we know that an unhealthy diet is associated with numerous diseases and conditions in children, including obesity. Obesity is a major public health problem in Australia, with around one in four Australian children overweight or obese. Furthermore, obesity in childhood increases the risk of obesity in later adult life, along with the risk of various chronic diseases, including cardiovascular disease and diabetes, various cancers and stroke. Because diet is so strongly associated with obesity and other diseases, it is important to establish which types of families might be buying unhealthy foods for their children. For example, is it less educated people who are buying these foods? Or could it be economically challenged people who are more likely to buy these foods? 

 Could socioeconomic status be associated with children's diets over time?

Astonishingly, our project at Murdoch Children's Research Institute found that children in the lowest, compared to the highest socioeconomic group, had around 22 times the odds of belonging to the unhealthiest rather than the least unhealthy pattern over time. In our recent study, using data collected from the Longitudinal Study of Australian Children, we investigated which socioeconomic factors early in life best predict childhood and adolescent diets from 2-3 to 10-11 and from 4-5 to 14-15 years of age, in two groups of approximately 5000 children.

Previous studies have shown that higher socioeconomic status and maternal education are associated with healthier child and adolescent diets, whereas lower socioeconomic status and maternal education, and higher household disadvantage, are associated with unhealthier child and adolescent diets. However, these studies are restricted by short follow-up periods of a maximum of 6 years, few consecutive dietary measurements and have only looked at one group of children at once.

We looked at childhood and adolescent dietary trends, measured in three different ways, from 2-3 to 10-11 and from 4-5 to 14-15 years of age. The first of these measures, dietary scores, looked at how children's diets adhered to the 2013 Australian Dietary Guidelines; the other two measures looked at trends in statistically derived 'healthy' and 'unhealthy' patterns. We measured diet every two years and at each time point, recorded the child's consumption of particular food or drink items in the last 24 hours. These foods or drinks included fruit, vegetables, water, dairy products, soft drinks, sweet foods, chips and processed meat products. We investigated how various socioeconomic factors, measured early in childhood, were associated with child and adolescent dietary trends. The factors that we considered were parental education, remoteness area, parental employment, income, food security, home ownership, socioeconomic position (which consisted of education, occupation and income combined) and neighbourhood disadvantage.                                                  

Generally, socioeconomic position and parental education were strongly and consistently associated with children having the least healthy and unhealthiest trends in dietary scores, healthy patterns and unhealthy patterns over time. However, income and neighbourhood disadvantage were not associated with diet. 

What do our findings mean and what are the next steps?

Our study demonstrates that children's diets are influenced by family socioeconomic status (specifically, socioeconomic position and education) more than by area level socioeconomic status (specifically, remoteness area and neighbourhood disadvantage). Education may lead to improvements in children's dietary trends by increasing parents' nutritional knowledge and also by leading to an ability to use and understand information on nutritional labels. We recommend that future researchers should investigate how parental health behaviours (fruit and vegetable consumption, alcohol, smoking and physical activity) are associated with children's diets over time. They should also determine how and when these dietary trends are associated with obesity and other health outcomes.

Some quick tips

There are many practical tips to help parents to encourage their children to adopt and maintain a healthy diet.

  • Firstly, even though it can be tempting to be persuaded by nagging children, parents should make a special attempt to stick to their shopping list. This might mean quickly moving from aisle to aisle to avoid purchasing unhealthy foods from the front and back of aisles.
  • Parents should encourage children to eat plenty of fruits and vegetables of different colours and types, a wide variety of grain foods, reduced fat dairy products, lean meat and poultry, and legumes/beans.
  • Try to make eating fun by using various colours of vegetables.
  • Discourage children's intake of sugary drinks, such as soft drinks, by replacing them with water.
  • Parents should review the Australian Dietary Guidelines for children.

Our study illustrates the importance of continuously educating parents about the value of healthy eating, both for themselves and their children. Healthy education programs, targeted to both children and parents, have already been shown to be successful in improving children's diets. However, our study shows that it is important to continuously educate parents over a few time periods as their children grow and develop, and on current nutritional education issues.