The relationship between childhood weight, dental caries and eating practices in children aged 4–8 years in Australia, 2004–2008


Address for correspondence: Dr M Hooley, School of Psychology, Deakin University, 221 Burwood Highway, Burwood, Vic. 3125, Australia. E-mail:


What is already known about this subject?

    What is already known about this subject?
  • Childhood obesity is a significant problem in Western and now also in developing countries.
  • Early development of dental caries in childhood is also a growing problem.
  • Significant interest in the relationship between dental caries and childhood obesity in recent years but the nature of the relationship has been contentious.

What this study adds?

    What this study adds?
  • This was the first study to investigate the nature of the relationship between dental caries and BMI in a large representative sample of Australian children.
  • The findings of this study contribute to the literature by suggesting that dietary interventions designed to reduce the incidence of dental caries may also reduce overweight and obesity in children.
  • Researchers and policy makers should consider the possibility that interventions designed to reduce children's consumption of fatty foods might inadvertently encourage the increased consumption of sweet foods, particularly in children who have curbed their fat intake.


The association between overweight/obesity and dental caries in children is contentious with studies variously reporting positive or negative associations between the two conditions. Since 1995, Australia has experienced a rise in the prevalence of both conditions in its children. This study investigated the association between child weight, diet and dental problems in a nationally representative sample.


Data from 4149 children (51.5% male) participating in the Longitudinal Study of Australian Children (LSAC) were used. The LSAC is a longitudinal study collecting data from a large representative cohort of Australian children; data from the first three waves were included with children aged 4–5 years, 6–7 years, and 8–9 years. Multivariate cross-sectional and prospective analyses were conducted to determine the relationships between child weight, diet and dental problems.


Overweight/obesity was associated with sweet drink consumption and dental problems associated with consumption of fatty foods and sweet drinks. Underweight was associated with dental problems cross-sectionally, but both underweight and overweight at age 6–7 years predicted dental problems at age 8–9 years.


Dental caries and body weight are influenced by diet. Overweight children may be consuming less fatty food but appear to be consuming more sweet drinks than normal-weight children, which can lead to both increased weight and dental caries. Dietary interventions designed to reduce the development of dental caries may also reduce the development and maintenance of overweight.