Obesity Influences the Severity of the Flu

Obesity is one of the most influential body conditions on health status. Below you will learn how obesity influences the flu and its severity.
Obesity Influences the Severity of the Flu
Maria Marin Garcia

Written and verified by the nurse Maria Marin Garcia.

Last update: 20 October, 2022

Obesity is considered one of the most prevalent nutritional problems in the Western world, and is a health priority. It has even been shown that obesity influences the severity of the flu.

According to the World Health Organization (WHO), there are more than 1 billion overweight people in the world, 300 million of whom are obese. The relationship between influenza and obesity will be discussed below.

Is obesity a risk factor?

Primarily, obesity is defined as an excess amount of body fat or adipose tissue. Numerous studies have proven the increase in the probability of suffering from a vast range of diseases with a considerable increase in weight. An example is the risk of suffering from pathologies such as the following:

  • Cardiovascular disease: A 20% weight loss in obese people could reduce the risk of cardiovascular disease by 40%.
  • Arterial hypertension: This factor, in turn, increases the risk of suffering cardiovascular diseases.
  • Diabetes: Increases the risk of hyperinsulinemia and glucose intolerance and decreases insulin resistance.
  • Colon cancer: About 50% of colon cancer cases are related to environmental and lifestyle factors, including obesity.
  • Arthrosis: Due to the weight accumulated in bones and joints.
  • Uterine and breast cancer, especially after menopause.
  • Biliary pathologies: In most cases, this is due to an increased amount of cholesterol in the bile because the body tries to eliminate it.
  • Increased mortality: Obesity leads to reduced life expectancy and increased complications in the process of many diseases.

Obesity influences the severity of the flu, but how?

As we have already seen, obesity influences the risk of suffering from diseases and can even cause them to appear. Recently, a study in mice has given clues about the influence of obesity on the severity of the flu, caused by the influenza virus.

The American Society for Microbiology published an article explaining the main cause of the obesity-flu link: obese people don’t have good immune responses or defense against viruses. This is summarized by the ease with which the virus can enter the organism and replicate quickly.

To prove this, the researchers compared a sample of infected fit mice with a normal weight and another of obese mice with the influenza virus. It was seen that there’s greater virulence, or ability to produce disease, among obese mice.

But in what way does obesity influence influenza?

Obesity and the flu.
Childhood obesity is a silent epidemic with serious health sequelae.

Generally speaking, all of us create an immune or defense response to any infection. In fact, many of us can come into contact with the causative agent of many diseases and not be infected because our defense system eliminates it easily.

In the case of overweight or obese people, the immune system doesn’t  work in the same way; it needs extra effort to cope with pathologies. The virus enters the body more quickly and, by making mistakes in protection against infections, it’s easier for a disease to form.

In addition, studies seem to suggest that by having more fat in the body, the fatty acids that cover our cells allow viruses to enter more easily.

Therefore, in the case of the flu, if it infects us and we don’t deal adequately with it, the situation will worsen. That is to say, the severity of the flu in this type of person will be more complex and evident.

Obesity influences the severity of the flu

Suffering any respiratory disease, added to an alteration of our natural protection system or immune system, increases the risk of complications.

In the case of the flu, it has been proven that having excess body fat is considered a very influential risk factor in the transmission and evolution of the influenza virus, better known as the common flu.

All cited sources were thoroughly reviewed by our team to ensure their quality, reliability, currency, and validity. The bibliography of this article was considered reliable and of academic or scientific accuracy.

  • OPS/OMS | Cuáles son las 10 principales amenazas a la salud en 2019 [Internet]. [cited 2020 May 13]. Available from: https://www.paho.org/hq/index.php?option=com_content&view=article&id=14916:ten-threats-to-global-health-in-2019&Itemid=135&lang=es
  • Autónoma U. Obesidad como factor de riesgo en enfermedades respiratorias – Centro de Comunicación de las Ciencias [Internet]. [cited 2020 May 13]. Available from: https://ciencias.uautonoma.cl/noticias/obesidad-como-factor-de-riesgo-en-enfermedades-respiratorias/
  • Honce R, Karlsson EA, Wohlgemuth N, Estrada LD, Meliopoulos VA, Yao J, et al. Obesity-related microenvironment promotes emergence of virulent influenza virus strains. MBio. 2020 Mar 1;11(2).
  • Honce R, Karlsson EA, Wohlgemuth N, Estrada LD, Meliopoulos VA, Yao J, et al. Obesity-related microenvironment promotes emergence of virulent influenza virus strains. MBio. 2020 Mar 1;11(2).
  • Martín V, Castilla J, Godoy P, Delgado-Rodríguez M, Soldevila N, Fernández-Villa T, et al. Índice de masa corporal elevado como factor de riesgo de hospitalización por gripe: estudio de casos y controles. Arch Bronconeumol. 2016 Jun 1;52(6):299–307.

This text is provided for informational purposes only and does not replace consultation with a professional. If in doubt, consult your specialist.