People who are overweight or obese are at a much higher risk of much more severe disease and even death from Covid-19, and one new study suggests that losing weight can reduce that risk.
“We are overwhelmed with the volume of patients that have really made that connection between obesity and Covid and the need for them to get appropriate care,” said Cody Stanford, who is also an assistant professor at Harvard Medical School.
Obesity and the increased risk of Covid-19
Dozens of studies have shown similar results.
Does losing weight reduce Covid-19 risk?
The increased risk has led many to wonder if losing weight might keep them from catching or getting sicker with Covid-19.
“There’s no question, in controlled trials with people who are obese and have heart failure, that if they go through a weight reduction or an exercise program or a combination, and we look at this marker of how they are doing, the answers to that are yes, there is evidence that weight loss is a good thing,” Kass said.
The study, looking at records from 20,212 people for more than six years, was funded by a grant from Medtronic, which makes devices for weight loss surgery.
The rates of positive Covid-19 tests were similar in the surgical and control groups: 9.1% and 8.7%, respectively. The weight loss among the group that had surgery was associated with a lower risk of hospitalization, need for supplemental oxygen and severe symptoms from a Covid-19 infection. This patient group also had a 53% lower 10-year cumulative incidence of all-cause non-Covid mortality, compared with the control group.
“The findings suggest that obesity can be a modifiable risk factor for the severity of Covid-19 infection,” the study said.
Dr. Steven Nissen, a cardiologist with Cleveland Clinic who co-authored the study, said it’s important to understand that weight loss is the key with this study, not the surgery itself.
The surgery just happens to be an effective way to lose weight.
“Losing weight is completely reversible,” Nissen said. “As far as we can tell, if you lose weight, then your risk of serious Covid and Covid morbidity and mortality goes way down.”
Why obesity is a threat
Obesity is a problem with Covid-19 for a variety of biological reasons.
“Fat cells are living cells, and as soon as you start to accumulate them, they’re essentially impacting your immune system negatively,” Popkin said. “From the word go, they’re inflamed.”
The importance of taking obesity seriously
Experts say the problems that obesity brings in this pandemic have been significantly underestimated.
“There’s not a country in the world that has less than 20% of adults with obesity,” Popkin said.
The US has one of the highest rates of obesity in the world, at more than 42% of the adult population, according to the CDC. And that’s probably a conservative number, because those statistics come from 2018. More than 73% of adults are considered overweight. And while the numbers aren’t as high for children, more than 20% of those 6 to 19 have obesity, and more than 13% of children 2 to 5 do.
“I think people don’t see obesity as the disease that it is. They think of it as a lifestyle choice,” Cody Stanford said. “A lot of people think those people just need to eat less and exercise more, but if that mantra worked, we wouldn’t have the prevalence of obesity that we have now.”
So what should people do?
Cody Stanford said she tells her patients not to focus on losing a certain number of pounds. Instead, they should be thinking in terms of inches. She’ll even give a target waist circumference: less than 35 inches in women and less than 40 inches in men.
Obesity is not just about weight or BMI, it’s about where that weight is distributed.
Generally, abdominal fat is one of the most dangerous kinds. The fat in the stomach area grows deep inside the body and wraps around vital organs. The liver borrows this fat and turns it into cholesterol that can sneak into the arteries and start collecting there. When that happens, the arteries start to harden, and this can lead to a heart attack or stroke.
This deep layer of belly fat is also what makes the body insulin-resistant and keeps it in a constant state of chronic inflammation. “When you add the inflammation of Covid on top of it, it can increase the risk of severe illness,” Kumar said.
A better central distribution of weight is key, she said.
“If that were better, they would likely have fewer complications from Covid and fewer deaths,” Cody Stanford said. “Just looking at the weight in and of itself without looking at the whole picture would be a flawed way of thinking of it.”
Based on studies of other diseases, Popkin says, even a person who is overweight but loses 5 pounds can see improvement in their diabetes and hypertension.
“Any weight loss is a positive at nearly any weight level,” he said. “Just marginal weight gain can impact us health-wise.”
Popkin added that weight loss is not nearly as protective as a vaccine or a booster.
“But certainly, it will have some benefit,” he said — especially coming out of the holiday season.