Many of the victims of COVID19 are people with compromised breathing. Something that may help is intermittent fasting. A study of asthma sufferers who tried an intermittent fasting protocol showed dramatic improvement across the board. This is mentioned in James B. Johnson's book about intermittent fasting. Intermittent fasting has many varieties, all involving either a few days of semi-fasting per week, or an interval each day of fasting, equivalent roughly to skipping a meal. The positive effects include lowering inflammation, overcoming diabetes, vastly improving hypertension, etc. etc. There are numerous books available about it, such as "Delay, Don't Deny" by Gin Stephens, and "The Fast Diet" by Mosley and Spencer. In this time of scrutinizing what it is that causes vulnerability to disease, I believe intermittent fasting will be revealed to be a key to health, and not just a means of losing weight, although of course that alone is a key to health.