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Fri, 22 Sep 2023

Study links obesity and sleep

Image: Shane McKnight

A new study has found people who sleep badly are also more likely to be obese.

James Cook University’s Abdul-Aziz Seidu was a co-author of the new study. He said obesity was once considered a problem only for high-income countries, but is now a serious public health concern worldwide.

“The prevalence of obesity has tripled within the last four decades, with 13% of the world's total population now classified as obese. In Australia, the 2014/15 national health survey showed nearly 28% of the Australian adult population were obese,” said Mr Seidu.

The study aimed to assess whether poor sleep duration and quality are significant risk factors for obesity in Australian adults aged over 15.

Mr Seidu said the team used the Household, Income and Labour Dynamics in Australia survey, which collects longitudinal data from more than 13,000 individuals within over 7000 households.

“We found the proportion of poor sleep duration – defined as less than 7 hours or more than 9 hours - amongst obese adults is 43%, compared to 32% among those with a healthy weight. Poor sleep quality amongst obese adults was measured at 36%,” said Mr Seidu.

He said poor sleep duration and quality boosts the secretion of hormones and exacerbates the risk of being obese, while lowering appetite-suppressing blood leptin levels and raising appetite-promoting blood ghrelin levels.

“From a behavioural perspective, the likelihood of unhealthy dietary habits is high amongst individuals who have poor sleep duration and quality,” said Mr Seidu.

He said obesity is strongly associated with the development of a raft of chronic health conditions and exacerbates the risk of mortality amongst people with existing health conditions.

Mr Seidu said more than 36% of survey participants in the survey reported poor sleep length and more than 28% poor sleep quality in 2021.

“Apart from its association with obesity, sleeping too little or too much is also independently associated with a high risk of diabetes, hypertension and cardiovascular diseases, while poor sleep quality is significantly associated with a high risk of depression.

“Enacting policies that raise public awareness of the significance of good sleep hygiene and encouraging healthy sleeping habits should be considered to address the alarming rise in the obesity rate and other direct effects of poor sleep.”

Mr Seidu said sleep is a complex multidimensional phenotype and further studies employing different study designs such as Randomized Clinical Trials are required to generate more evidence.


Abdul-Aziz Seidu
E: abdulaziz.seidu@jcu.edu.au