Obese people have a tougher time fighting COVID-19, even if they have a milder form of the virus, a new study finds.
Researchers looked at more than 500 patients who tested positive for COVID but didn't require hospitalization. Teens and adults who were overweight or obese had more symptoms, including cough and shortness of breath, than those of normal weight.
"Even when infected with similar amounts of virus, overweight and obesity are risk factors for greater severity of COVID-19 symptoms," said lead researcher Dr. Pia Pannaraj, a pediatric infectious disease specialist at Children's Hospital Los Angeles.
"COVID-19 vaccination of all individuals, and especially those with overweight and obesity, is important to prevent severe COVID-19," she added.
Obesity can lead to more severe COVID-19 because it's tied with other conditions known to make people sicker if they catch the virus, Pannaraj said. "Individuals with obesity may have the beginnings of diabetes, heart disease or other chronic diseases before it can be detected," she added.
Losing weight may help ward off COVID-19 and make it less life-threatening should you get it, Pannaraj said. "Maintaining a healthy lifestyle with healthy eating and exercise is beneficial for many reasons," she said. "Being able to fight off infections such as COVID-19 is just one more reason."
About two-thirds of the participants in this new study were overweight or obese -- similar to U.S. and worldwide rates, the authors noted.
The researchers found that COVID severity in children under 12 was not affected by excess weight. But for teens and adults, they uncovered a different story.
The overweight or obese participants had more symptoms than normal-weight individuals (three vs. two), including more cough and shortness of breath.
Overweight or obese teens were more likely to have symptoms than normal-weight teens (67% vs. 34%) and they had longer lasting respiratory symptoms (median 7 days vs. 4 days), compared with normal-weight teens, the researchers found.
The data confirms the benefit of COVID-19 vaccines for overweight and obese teens and adults, Pannaraj's team concluded.
One expert not part of the study, Dr. Nicholas Kman, pointed out that even vaccinated patients can get a mild case of COVID-19.
"We also know that when the immune system is compromised, like in severe obesity, we don't mount as good a response to the vaccine," said Kman, an emergency medicine physician at Ohio State University Wexner Medical Center in Columbus.
"This is why it is important for patients with risk factors, like elderly age and obesity, to get the booster vaccine when it is their turn," he said. "The best thing an unvaccinated patient, with or without risk factors, can do is get the vaccine and then work on those healthy lifestyle changes."
Dr. David Katz is president of True Health Initiative, which promotes healthy living as the best way to prevent disease. He said that throughout the pandemic, COVID-19 has targeted select groups.
"Even before a pandemic was declared, data from China and South Korea indicated that SARS-CoV-2 was not a one-size-fits-all threat," said Katz, who wasn't involved with the study.
Advanced age and chronic conditions, including heart disease, diabetes and obesity, were associated with elevated risks of severe infection, Katz said. This pattern persisted as COVID-19 spread around the world, leading to marked differences in hospitalization and deaths among populations.
This paper expands that view of variable risk for worse outcomes to include those with milder disease, Katz said.
"It also reminds that the slow-motion pandemics of obesity and chronic illness have made the acute COVID pandemic far worse than it needed to be, both among those hospitalized, and even among those with milder disease," he said.
"These findings add to the already compelling case for defending against the threat of acute pandemics by doing far more to promote general good health, including healthy weight, for the population at large," Katz said.
The report was published Oct. 20 in the journal Influenza and Other Respiratory Viruses.
For more on COVID-19 and obesity, see the U.S. Centers for Disease Control and Prevention.
SOURCES: Pia Pannaraj, MD, MPH, pediatric infectious disease specialist, Children's Hospital Los Angeles; David Katz, MD, MPH, president, True Health Initiative; Nicholas Kman, MD, emergency medicine physician, Ohio State University Wexner Medical Center, Columbus; Influenza and Other Respiratory Viruses, Oct. 20, 2021