In the early weeks of the COVID-19 outbreak in France, doctors noticed that, along with the older people who were more likely to be hospitalised with severe symptoms, young and obese people were also ending up seriously ill.

Since then, several studies have concluded that obesity ranks second behind old age as a risk factor for severe illness and death from the virus.

One study, published a week ago in the journal Obesity concluded: “The present study showed a high frequency of obesity among patients admitted in intensive care for SARS‐CoV‐2. Disease severity increased with BMI.”

In other words, the fatter you are, the sicker you’ll get.

The study, which found that many of these patients required mechanical ventilation, further concluded: “Obesity is a risk factor for SARS‐CoV‐2 severity requiring increased attention to preventive measures in susceptible individuals.”

The problem there, of course, is that overcoming obesity isn’t a short-term project, even with surgery. And at the moment, elective surgery isn’t easily accessed.

Obese and younger: Twice the risk of critical care

Doctors from New York University Langone Health, a large academic hospital system, performed a retrospective analysis of BMI (body mass index) and age of COVID-19-positive symptomatic patients. A BMI of 30 or more indicates obesity.

The results are contained in a report, not yet peer-reviewed, but available for public scrutiny by downloading a PDF here.

Of the 3615 individuals who tested positive for COVID-19, 1370 (or 37 per cent) were obese. (This is roughly on par with the US obesity rate of 40 per cent.)

But when BMI was analysed against the age of patients, and level of care required, a disturbing trend emerged: patients aged under 60, with a BMI between 30 and 34 were twice more likely to be admitted to acute or critical care, compared to patients with a BMI less than 30.

The authors concluded that patients aged less than 60 years “are generally considered a lower risk group of COVID-19 disease severity, (but) based on data from our institution, obesity appears to be a previously unrecognised risk factor for hospital admission and need for critical care.

“This has important and practical implications, where nearly 40 per cent of adults in the US are obese.”

America fears for many its fat people of the Midwest

The New York Times picked up on that fact, noting: “More than half of COVID-19 deaths in the United States so far have been in New York and New Jersey, but the new findings mean the coronavirus could exact a steep toll in regions like the South and the Midwest, where obesity is more prevalent than in the Northeast.”

Dr Roy Gulick, chief of infectious diseases at Weill Cornell Medicine, told the Times: “If obesity does turn out to be an important risk factor for younger people, and we look at the rest of the United States – where obesity rates are higher than in New York – that will be of great concern. We may see a lot more younger people being hospitalised.”

A Chinese study analysed the outcomes of 112 COVID-19 patients: 17 died, and 15 of those were either overweight or obese.

The authors concluded: “Higher BMI are more often seen in critical patients and non-survivor.”

A second Chinese study, published in The Lancet, concluded that “obesity, especially in men, significantly increases the risk of developing severe pneumonia in COVID-19 patients.

“As the 2019n-Cov may continue to spread worldwide, clinicians should maintain a high level of attention in obese patients. Obese patients should be carefully managed with prompt and aggressive treatment.”

In 2017-18, 31 per cent of Australian adults were obese, according to the Australian Institute of Health and Welfare.

The reasons why obesity is associated with severe COVID-19 illness are not yet clear, beyond a tendency to poor health and a vulnerability inflammation. We’ll back to you with more detail when it comes to hand.