New light on obesity

Posted on: September 1st, 2020 by Dr. Robert Kushner & Nalini Saligram

A new light has been shone on obesity in the last few months.

Obesity has always been known as a harbinger of many chronic diseases, but for the very first time a clear link has been established to an acute infectious disease – COVID-19. We, at Arogya World, a global health organization working to prevent Noncommunicable diseases (NCD) in India, wanted to learn about the links between obesity, COVID-19, and NCDs.  With about 42% of Americans having obesity this is an area of major public health concern.  So we spoke to Dr Robert Kushner, Professor of Medicine and Medical Education, Northwestern University Feinberg School of Medicine and Director, Northwestern Medicine Center for Lifestyle Medicine, to unpack all this for us, a few weeks ago, as part of Arogya World’s Emerge Stronger from COVID webinar series. Watch the recording (8 Aug 2020.)

We learned so much, and wanted to share it with more people through this article.

  • As is widely known, people with obesity are more likely to have other chronic diseases – diabetes, hypertension, cardiovascular disease, and sleep apnea.


  • In recent months, it has been widely accepted that obesity (body mass index [BMI] of 30 or higher) is a risk factor for severe illness from COVID-19 as are some underlying chronic conditions such as cancer, serious heart conditions, type 2 diabetes etc. (see what the CDC says here.)
  • These conclusions have been confirmed from recent data from the UK Biobank that shows a number of underlying conditions and socio-economic factors can increase the risk for severe illness from COVID.
Modifiable Risk Factors Relative Risk (RR) Non-modifiable Risk Factors Relative

Risk (RR)

Higher BMI / Obesity


Slow walking pace

Use of blood pressure meds





Older age

Male sex

Black ethnicity

Socioeconomic deprivation

Longstanding illness






*Ho FK, et al. medRxiv preprint doi:

  • Other studies have shown that those with obesity have an increased risk of death three to four times relative to those of normal weight.
  • Early data from New York revealed that among 5700 patients hospitalized with COVID-19, 41.7% had obesity (BMI ≥30 kg/m2) second only to hypertension (56.6%)- Richardson S, etl al. JAMA 2020;323(20):2052-2059

It turns out that obesity, by itself, is an independent risk factor for complications from COVID-19. This is what we know:

  • We know that obesity is associated with metabolic dysfunction and a chronic state of low-grade inflammation due to cytokines, small secreted proteins released by cells have a specific effect on immune function.
  • In COVID-19 infected individuals with obesity, the cytokines may surge during illness while protective T cells decline. This results in the so-called “cytokine storm” that is reported in many hospitalized COVID patients. Such exaggerated immune responses have been shown to potentially cause lung damage and result in diminished survival in patients.
  • Obesity may thus predispose someone to COVID complications, when the pre-existing low level of cytokines go into hyperdrive upon infection with the virus. Therefore people with obesity are more prone to severe illness and worse outcomes from COVID.
  • One additional point. Fat cells have high levels of the receptor to which the COVID – 19 virus attaches when it enters the body. In people with obesity, the virus can live longer as there is more fat tissue, causing prolonged and cascading infection and multiple organ dysfunction.


Furthermore, it is much harder in the hospital to manage COVID patients with obesity.  Because of their weight and large abdominal girth, it becomes more difficult to insert a breathing tube, harder to keep the patients prone (on their stomach), and tougher to manage their airways among other challenges.  In fact, we know, beyond any doubt, that individuals with obesity have increased risk of being admitted to a hospital if they get infected with COVID-19, once hospitalized of being admitted to Intensive Care Units, and then of requiring a ventilator and ultimately having higher mortality.  At each of these steps in COVID-19 disease progression, obesity leads to 2-4 fold higher risk and worse outcomes.


So what is one to do?  First, whether we have obesity or not, we should all practice what public health authorities tell us – wash hands frequently, practice social distancing, and importantly wear masks to avoid getting infected by COVID.  Dr Kushner and non profit organizations  like Arogya World also recommend a more disciplined lifestyle – eat right, exercise, get adequate sleep, and take active steps to reduce stress and take care of your mental well-being.  In fact, during COVID-19 times, some people have improved self-care – they eat more home cooked meals, avoid fast foods, do yoga, etc. – and have improved their resilience.


We commend British Prime Minister Boris Johnson who realized this when he was hospitalized from COVID-19 in April 2020, and has started an important campaign to get more Britons to lose weight.


We also commend the Mexican government for realizing that obesity puts people at risk for severe COVID-19 and for taking bold steps to fix that.  Different Mexican states have started in August 2020 to ban the sale of junk food to children under 18.

This is a landmark moment in public health. COVID-19 has highlighted the links between obesity, junk food consumption, diabetes, and negative outcomes from COVID. Bravo Mexico. Bold policy decisions like this can help our generation really tackle obesity and NCDs, and prepare our people from the next pandemic at the same time. It will also help the world meet Sustainability Development Goal #3 – health and wellbeing for all.