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.
Ethically, it would be nearly impossible to do randomized controlled trials to determine this, according to
Dr. David Kass, a cardiologist at Johns Hopkins Medicine. But scientists have seen how weight loss can help in trials for other diseases with similar problems.
"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.
A large retrospective study
published last week in JAMA Surgery suggests that substantial weight loss makes a difference.
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."
This is about as soft and as dubious as a highly biased study could possibly be. Weight is not going to affect if you catch COVID. It's not proven in any way to affect if your COVID is serious or not. But yes, if you are hospitalized with COVD and you have high blood pressure or heart issues or other health issues because you are grossly overweight, that is going to impact the outome.