As early as the first few weeks of the COVID-19 pandemic, physicians were already reporting that several pre-existing chronic health concerns appeared to be more commonly present in individuals with a more severe case of infection. These individuals include those who have:1 

  1. Suppressed immune systems
  2. High blood pressure or serious heart disease
  3. Liver or kidney disease 
  4. Lung disease, such as asthma
  5. Diabetes
  6. Obesity

It’s easy to understand that an individual with a chronic health condition might have a greater challenge when faced with a serious infection. But it may be harder to understand the connection to body weight, and why excess weight would increase the risk of a more serious outcome.

First, you should understand that even if you don’t think of excess body weight in the same category as other chronic health concerns, in 2013 the American Medical Association classified obesity (defined as having a body mass index – BMI – of 30 or higher) as a disease2 because it has a substantial adverse impact on health and longevity (Calculate your BMI).

Obese individuals account for more than 40 percent of middle-aged U.S. adults, and obesity is associated with increased rates of diabetes, heart disease, liver disease, some cancers, mental health disorders, arthritis, and a generally shortened lifespan.

Although we don’t often talk about it in these terms, obesity has been referred to by many as an epidemic,3 given the profound number of people impacted and the costs attributed to living with excess weight. 

So what is going on with excess body weight and immune health? Overweight and obese individuals have excess amounts of body fat, and it is fat cells that make inflammatory proteins such as TNF-α, IL-6, IL-1β, IL-18, and MCP-1. Fat cells also make other compounds, such as leptin and adiponectin, that have a modulating effect on overall immune function.

Although the mechanism is not completely understood, it is believed that having a higher than normal level of these compounds continually circulating can desensitize the immune system, so when an actual infection occurs the immune system is less prepared to respond.4 In addition, overweight and obese individuals are likely to have lower levels of vitamin D and more oxidative stress – both of which can negatively impact normal immune health. 

When researchers study the impact of obesity on immune function, respiratory illness is a consistent area of concern. For example, we know that excess body fat increases the risk for contracting the flu (influenza), as well as being hospitalized, requiring intensive care, acquiring a secondary infection such as bacterial pneumonia, and death.5 

Moreover, obesity is associated with decreased vaccine efficacy. With the flu vaccine, for example, obese individuals experience a more rapid decline of antibody levels and have an altered response compared to non-obese individuals, which results in overall weaker immunity.6 An additional challenge is that it is often harder to provide advanced respiratory support in higher-weight individuals because intubation can be more difficult.

What can you do?

When it comes to managing weight, there is no one-size-fits-all solution. It often takes a multi-factorial approach, including diet and exercise, and sometimes medication, hormone modulation, or even surgery in cases of severe obesity.

If you have a chronic struggle with your weight – especially if you have other health conditions – then it is definitely best to start by talking to your health-care professional. If you are generally healthy and have lesser amounts of weight to lose, then you might find success with self-guided weight management.

The Centers for Disease Control (CDC) has general guidance available for individuals at a higher risk of complications from COVID-19, including obesity and related disorders like diabetes. The good news is that even a small amount of weight loss (just 5%) can have significant benefits for health,7 and this can be achieved by most people with the right changes and support.


  1. CDC. Coronavirus Disease 2019 (COVID-19). Centers for Disease Control and Prevention. [Accessed May 18, 2020.]
  2. AMA classifies obesity as a disease. Obesity Medicine Association. [Accessed May 18, 2020.]
  3. Mitchell N, Catenacci V, Wyatt H, Hill J. Obesity: overview of an epidemic. Psychiatr Clin North Am 2011;34(4):717-732. 
  4. Milner J, Beck M. Micronutrients, immunology and inflammation: the impact of obesity on the immune response to infection. Proc Nutr Soc 2012;71(2):298-306. 
  5. PubMed Central Link. [Accessed May 18, 2020.]
  6. Sheridan P, Paich H, Handy J, et al. Obesity is associated with impaired immune response to influenza vaccination in humans. Int J Obes 2012;36(8):1072-1077. 
  7. Magkos F, Fraterrigo G, Yoshino J, et al. Effects of moderate and subsequent progressive weight loss on metabolic function and adipose tissue biology in humans with obesity. Cell Metab 2016;23(4):591-601.

An important note: No dietary supplement can diagnose, treat, cure or prevent any disease, including COVID-19. With the ongoing COVID-19 pandemic, it is especially important to understand that no dietary supplement, no diet, and no lifestyle modifications – other than the recommended social distancing and hygiene practices – can prevent you from being infected with the COVID-19 virus. No current research supports the use of any dietary supplement to protect you from being infected with the COVID-19 virus.