Covid hit obese people way harder than their thinner counterparts. Being fat didn't make them catch the virus, but it made their outcomes worse.

Having a genetic disease is not due to being fat (although obesity affects your epigenetics and we are still learning what it's doing to the next generation) but there are a lot of chronic/ genetic diseases that are made worse by being fat.

Having an accident isn't due to being fat but any surgery you might need will have a higher risk of complications, and the recovery will be harder, meaning you are less likely to regain maximal function.

Obesity is the biggest modifiable risk factor for just about every preventable health problem. Doctors who tell their patients to try to lose weight, and better still hook them up with the help they need to do that, are being responsible and serving their patients the best way they can.