Being overweight may actually protect against life-threatening infections

GOTHENBURG, Sweden — Being overweight or obese is typically a pathway to health problems and disease. However, a recent study finds obesity may actually increase a person’s chances of surviving potentially deadly illnesses.

Researchers from the University of Gothenburg say people with bigger waistlines are less likely to die from severe bacterial infections than those who are slim and trim. Normally, being overweight or obese is a bad omen. Previous studies show excess weight increases the risk of developing certain forms of cancer, diabetes, or heart disease.

“In the context of most other diseases, overweight and obesity are disadvantageous. This applies to several types of cancer, cardiovascular disease and, in particular, COVID-19, in which a higher BMI is associated with higher mortality. Paradoxically, it’s the other way round here,” says study author Dr. Åsa Alsiö from Sahlgrenska Academy in a university release.

Body mass index (BMI), a value created by comparing a person’s height and weight, is a common measure doctors use to check whether a person has a healthy weight. For most adults, a healthy BMI score is between 18.5 and 24.9, while over 25 is overweight, and over 30 is obese. Obesity is a common problem in many nations. In the United States, more than two in five adults classify as obese, according to the CDC.

Normal weight leads to more deaths from bacterial infections?

Over nine months, the researchers studied 2,196 patients treated for bacterial infections at Skaraborg Hospital in Skövde, Sweden. The team discovered that having a high BMI raises the patient’s chances of survival in both the short and long term, at 28 days and one year after hospitalization, respectively.

In the “normal” weight group, 26 percent of participants died within one year of their infection, compared to just nine to 17 percent in those in the overweight to obese range. The study isn’t the first to find that weight may play a protective role against certain conditions.

The new findings confirm what scientists call the “obesity survival paradox,” or that being overweight or obese offers protections against bacterial infections.

“What we don’t know,” Alsiö continues, “is how being overweight can benefit the patient with a bacterial infection, or whether it’s connected with functions in the immune system and how they’re regulated. More knowledge is needed about how being overweight affects the immune system. One patient category it could be studied in is individuals undergoing bariatric surgery.”

“Globally, obesity is increasing at an alarming rate. More knowledge is needed to shed light on how body weight affects the body’s defenses against infection, so that treatment can be individualized,” adds co-author Dr. Gunnar Jacobsson.

Weight’s link to coronavirus

More knowledge about the links between weight and disease could help improve treatments for other diseases such as COVID-19.

“The COVID-19 pandemic has highlighted vulnerable patient groups, and overweight people have been hit hard. Maybe experience and handling of care for patients with severe bacterial infections can be used to improve the prognosis of COVID-19 and overweight,” Dr. Jacobsson concludes.

The findings appear in the journal PLOS One.

South West News Service writer Tom Campbell contributed to this report.