Combining lifestyle behaviours to explore obesity risk in school-aged children

One quarter of Australia’s young children are currently estimated to experience overweight and obesity.

If left untreated, childhood obesity can have acute and long-term implications on health and wellbeing, increasing risk factors for heart disease and other chronic conditions.

IPAN PhD student Ninoshka D’Souza has studied energy balance behaviours of school-aged children, such as diet, physical activity, sedentary behaviour, and sleep.

“Most previous evidence has examined these behaviours individually to understand and explore their effects on obesity. However, these health behaviours do not exist in isolation. Considering multiple behaviours together rather than examining them individually may give us a better understanding of childhood obesity,” Ms D’Souza said.  

Her systematic review explored the combined influence of these behaviours as lifestyle patterns, in children aged between 5-12 years.

Ms D’Souza examined evidence on the clustering of these four behaviours to identify underlying ‘patterns’ across behaviours in a given dataset.

Of 28 eligible studies, only six studies examined patterns for all four behaviours, with the remaining studies examining only 2-3 of the four behaviours of interest.

Findings

Having found a range of lifestyle patterns within the age group, the research team broadly classified these patterns into either a healthy, unhealthy or a mixed lifestyle pattern.

Healthy patterns comprised behaviours likely to protect against obesity (e.g. healthy diets, high physical activity, low sedentary behaviour, high sleep duration). Unhealthy patterns contained less desirable behaviours (e.g. unhealthy diets, low physical activity, high sedentary behaviour, low sleep duration). Mixed patterns contained a mixture of healthy and unhealthy behaviours.

The review identified that mixed patterns were most prevalent, and were reported in most studies. For girls, patterns comprising healthy diets, high sedentary behaviour, and low physical activity were observed. Boys on the other hand exhibited patterns comprising high physical activity and unhealthier diets but had similar sedentary behaviour levels to girls. Sleep did not appear to be a key feature of the patterns in this age group as children’s sleep durations were less varied.

Unhealthy patterns consisting of low physical activity and high sedentary behaviour were also frequently reported by studies. Unhealthy patterns were reported more frequently in children from lower socio-economic backgrounds.  Lastly, unhealthy lifestyle patterns were more often associated with overweight/obesity risk than healthy or mixed patterns.

Significance of the findings

Ms D’Souza said the review provided a more comprehensive picture of the influence of multiple behaviours on obesity compared to previous methods of examining individual behaviours.

“Children with unhealthy patterns were at increased risk of overweight/obesity, suggesting that the cumulative effect of multiple undesirable behaviours are particularly harmful and warrant appropriate intervention strategies to ensure these patterns do not track into adolescence,” she said.

“We found it was common to see different combinations of healthy and unhealthy behaviours, which highlights the complexity of lifestyle behaviours. For example, children who appear to be exhibiting healthy levels of one or two behaviours may still be at increased health risk based on levels of other behaviours.

Ms D’Souza added that breaking down findings by sex and socio-economic position highlight the need for specific future prevention and intervention strategies to ensure maximum impact on obesity reduction in children.

Given the limited number of studies identified that investigated all four behaviours, Ms D’Souza said a clear picture of the combined influence of energy balance behaviours on obesity could not be established.

“Lifestyle patterns, as opposed to individual behaviours, can help us understand and treat complex health outcomes such as obesity in children, but further studies are needed to comprehensively assess patterns comprising all four behaviours,” she said.

 

Ninoshka D’Souza is a PhD student at the Institute for Physical Activity and Nutrition, Deakin University. Her principal supervisor is Professor Kylie Hesketh. Ninoshka’s PhD thesis explores lifestyle patterns and adiposity in school-aged children. This blog highlights key findings from a published systematic review that forms part of her thesis.