Patients who are overweight or obese have more severe COVID-19 and are highly likely to require invasive respiratory support, according to a new international study. 

The research, led by the Murdoch Children's Research Institute (MCRI) and The University of Queensland and published in Diabetes Care, found obese or overweight patients are at high risk for having worse COVID-19 outcomes. They are also more likely to require oxygen and invasive mechanical ventilation compared to those with a healthy weight. 

MCRI researcher Dr Danielle Longmore said the findings, which highlighted the relationship between obesity and increased COVID-19 disease burden, showed the need to urgently introduce strategies to address the complex socio-economic drivers of obesity, and public policy measures such as restrictions on junk food advertising.  

"Although taking steps to address obesity in the short-term is unlikely to have an immediate impact in the COVID-19 pandemic, it will likely reduce the disease burden in future viral pandemics and reduce risks of complications like heart disease and stroke," she said.

The study looked at hospitalised SARS-CoV-2 patients from 18 hospitals in 11 countries including China, America, Italy, South Africa and The Netherlands. 

Among the 7244 patients aged 18 years and over, 34.8 per cent were overweight and 30.8 per cent were obese.   

COVID-19 patients with obesity were more likely to require oxygen and had a 73 per cent greater chance of needing invasive mechanical ventilation. Similar but more modest results were seen in overweight patients. No link was found between being overweight or obese and dying in hospital from COVID-19. 

Cardiovascular and pre-existing respiratory diseases were associated with increased odds of in-hospital deaths but not a greater risk for needing oxygen and mechanical ventilation. For patients with pre-existing diabetes, there was increased odds of needing invasive respiratory support, but no additionally increase in risk in those with obesity and diabetes. 

Men were at an increased risk of severe COVID-19 outcomes and needing invasive mechanical ventilation. In those aged over 65 years, there was an increased chance of requiring oxygen and higher rates of in-hospital deaths.

The University of Queensland's Dr Kirsty Short, who co-led the research, said almost 40 per cent of the global population was overweight or obese. 

"Obesity is associated with numerous poor health outcomes, including increased risk of cardiometabolic and respiratory disease and more severe viral disease including influenza, dengue and SARS-CoV-1," she said. 

Dr Short said while previous reports indicated that obesity was an important risk factor in the severity of COVID-19, almost all this data had been collected from single sites and many regions were not represented. Moreover, there was a limited amount of evidence available about the effects of being overweight or obese on COVID-19 severity. 

"Given the large scale of this study we have conclusively shown that being overweight or obese are independent risk factors for worse outcomes in adults hospitalised with COVID-19," she said.

MCRI Professor David Burgner, who co-led the research, said the data would help inform immunisation prioritisation for higher-risk groups.

"At the moment, the World Health Organization has not had enough high-quality data to include being overweight or obese as a risk factor for severe COVID-19 disease. Our study should help inform decisions about which higher-risk groups should be vaccinated as a priority," he said. 

Researchers from Radboud University Medical Center in The Netherlands, University of Bern in Switzerland, the Doherty Institute, University of Queensland, Washington University, Melbourne University, Monash University and an international BMI-COVID consortium also contributed to the study.  

Publication: Danielle K. Longmore, Jessica E. Miller, Siroon Bekkering, Christoph Saner, Edin Mifsud, Yanshan Zhu, Graham Colditz, Kirsty R. Short, David P. Burgner and an international BMI-COVID consortium. 'Outcomes in patients with overweight and obesity hospitalized with COVID-19: an international, multi-center analysis.' Diabetes Care. DOI: 10.2337/dc20-2676

Available for interview: 

Dr Danielle Longmore, MCRI researcher 
Dr Kirsty Short, The University of Queensland  
Professor David Burgner, MCRI Group Leader, Inflammatory Origins

Media Contacts: 

Bridie Byrne
MCRI communications specialist
+61 3 9936 6211/ 0403 664 416

Dominic Jarvis
UQ Engagement Officer (Media & Communication)
+61 7 3365 4043 /  0413 334 924
[email protected] MCRI

The Murdoch Children's Research Institute (MCRI) is the largest child health research institute in Australia committed to making discoveries and developing treatments to improve child and adolescent health in Australia and around the world. They are pioneering new treatments, trialling better vaccines and improving ways of diagnosing and helping sick babies, children and adolescents. It is one of the only research institutes in Australia to offer genetic testing to find answers for families of children with previously undiagnosed conditions.

About UQ

For more than a century, The University of Queensland has educated and worked with outstanding people to deliver knowledge leadership for a better world. The most prestigious and widely recognised rankings of world universities consistently place UQ among the world's top universities. UQ has also won more national teaching awards than any other Australian university. This commitment to quality teaching empowers our 53,600 current students, who study across UQ's three campuses, to create positive change for society. Our research has global impact, delivered by an interdisciplinary research community of more than 1500 researchers at our six faculties, eight research institutes and more than 100 research centres.


There was no specific project funding for the study. JEM was supported by a fellowship from the DHB Foundation, Australia; SB is supported by the Dutch Heart Foundation (Dekker grant 2018-T028); EM is supported by the WHO CCRI funded by the Australian Commonwealth Government, Department of Health; KRS was supported by the Australian Research Council (DE180100512); DPB was supported by a National Health and Medical Research Council (NHMRC) Australian Investigator Grant (GTN1175744). Research at the Murdoch Children's Research Institute is supported by the Victorian Government's Operational Infrastructure Support Program.