Is COVID-19 Mortality, Disease Severity Associated With Obesity?

Is obesity associated with adverse COVID-19 outcomes, including increased mortality? A meta-analysis summarized findings of existing evidence on the subject.

Although obesity is not associated with COVID-19 mortality, it is associated with other adverse outcomes of COVID-19 that are related to severe disease, according to the results of a meta-analysis published in the journal Obesity Medicine.

Recognizing that the literature covering COVID-19 is growing each day, the researchers postulated that the evidence of the presence or absence of a relationship between COVID-19 and adverse outcomes merits revisiting. The current meta-analysis therefore summarized the findings of pooled evidence on the association between obesity and COVID-19–related adverse outcomes and mortality.

The investigators searched relevant databases through August 9, 2020, retrieving all retrospective and prospective studies that fulfilled the following criteria: (1) the study provided event rate data on obesity and any adverse outcome; (2) the study presented data based on categories of obesity status or body mass index (BMI); (3) the patients evaluated were adults from the general population of those who had been diagnosed with COVID-19; (4) the studies were written in English. 

In order to minimize selection bias, studies were excluded if they specifically sampled individuals with certain disorders, including organ transplant recipients, those with cancer, and those with HIV. The researchers also excluded articles that were identified as clinical trials, case reports, reviews or systematic reviews, meta-analyses, conference abstracts, international surveys, correspondences, letters to the editor, and animal experiments.

Data from the studies selected were analyzed with the use of Comprehensive Meta-Analysis V2 random effects model to calculate odds ratios (ORs) and 95% confidence intervals (CIs) of infection severity and mortality associated with obesity in patients with COVID-19. An initial total of 2259 studies were identified, with 57 studies that comprised 272,882 patients ultimately included in the quantitative analysis. All of the studies included in the meta-analysis had been published in 2020.

Data analysis showed that although obesity is not associated with mortality from COVID-19 (OR, 1.1; 95% CI, 0.8-1.3), it is associated with other adverse outcomes
(OR, 2.4; 95% CI, 1.7-3.3). In fact, heterogeneity measured by I2 was 79% for mortality compared with 97% for severity, with an I2 value of >50% known to be indicative of considerable heterogeneity.

Various terms were used in the studies to characterize severity, including hospital admission, intensive care unit (ICU) admission, severe symptoms, mechanical ventilation, and mortality. COVID-19 severity refers to oxygen saturation of less than 90% on room air, respiratory rate of more than 30 breaths per minute in adults, or signs of severe respiratory distress (ie, accessory muscle use, inability to complete full sentences), as defined according to World Health Organization guidelines.

Limitations of this meta-analysis include the fact that different studies use different definitions of severity. Further, studies define obesity with the utilization of different BMI cut-off points.

The researchers concluded that the findings from the current study demonstrate that obese patients with COVID-19 “should be monitored for likely progression to severe outcomes.”


Abumweis S, Alrefai W, Alzoughool F. Association of obesity with COVID-19 diseases severity and mortality: a meta-analysis of studies. Obes Med. Published online June 9, 2022. doi:10.1016/j.obmed.2022.100431