Three factors that predict risk of adolescent obesity

A study led by the Murdoch Children’s Research Institute (MCRI) found that a child’s and mother’s body mass index (BMI), and the mother’s education level, can be used to predict the onset or resolution of weight problems by adolescence, especially from age 6–7 onwards.
 
The prevalence of being overweight or obese at the age of 14–15 years was 13% among children with none of these three risk factors at age 6–7, compared with 71% among those with all risk factors.
 
Co-author Dr Kate Lycett told newsGP the simple test has the potential to be valuable for clinicians, including GPs, as well as patients.
 
‘Childhood presents a window of opportunity where we can set healthy habits, which is important as we know these track into adolescence and adulthood,’ she said.
 
‘We also know that the risk of type 2 diabetes and poor cardiometabolic health among children with overweight or obesity who resolve to normal weight by adulthood are similar to those who had never been overweight or obese.
 
‘[However], for a lot of children who are presenting to, for example a GP or a paediatrician, the primary purpose of their visit often isn’t about their overweight or obesity, it’s generally about another condition.
 
‘So while clinicians have that opportunity to try and raise it, it can be tricky because the parents or patient may not be expecting it … [and] doctors may not want to raise these questions if the patient is likely to resolve the issues on their own.’
 
According to the study, each one-unit higher BMI when the child is aged 6–7 triples the odds at 14–15 of developing weight problems, while simultaneously halving the odds of resolution.
 
Similarly, every one-unit increase in the mother’s BMI when the child is aged 6–7 increases the chance at 14–15 of developing weight problems by 5% and decreases the odds of resolution by about 10%.
 
Mothers having a university degree is associated with lower odds of a child being overweight and obese at 2–5 years of age, and higher odds of resolving obesity issues by adolescence.
 
Dr Lycett said BMI proved a useful and objective tool compared to other more subjective measures.
 
‘[It] is easily measured and reflects diet and exercise choices, but is free from the challenges of assessing physical activity and diet in a standard clinical appointment, such as recall bias,’ she said.
 
‘It still requires clinical judgment, as it’s not perfect by any means, but it’s still better than what we previously had, which is nothing.’
 
Data was sourced from the Longitudinal Study of Australian Children and included 3469 participants at birth and 3276 participants at kinder. The BMI and education levels of fathers were not able to be fully analysed due to incomplete data.
 
The study also examined how combinations of 25 potential short clinical markers, such as time breastfeeding and the amount of outdoor activity at various ages, could predict weight issues, as well as resolution, by ages 10–11 and 14–15.
 
However, while the three factors identified above were able to make predictions with about 70% accuracy, short questions about poor diet, low physical activity and other common lifestyle factors were not predictive of weight outcomes.

adolescence childhood obesity research