That’s honestly kind of insulting to say that, and it shows a lack of awareness on your own part. You’re making one hell of an assumption that people aren’t informed and that they’re making a diagnosis without putting any thought behind it.
I’m not out of line in thinking that people can’t diagnose Joe Biden of being mentally unfit. People couldn’t definitively diagnose Trump with narcissistic personality disorder, and he didn’t have a known disorder that could interfere in a diagnosis. Biden has a well documented stutter, making it hard for any observer to parse his communication disorder from cognitive impairment.
People who are informed would recognize this, and even those willing to diagnose politicians from TV appearances would need solid examples of abnormal behavior that could only be explained by cognitive impairment. I don’t take armchair diagnosis seriously because I have some expertise in psychology. People want a reason to have someone other than Biden, so they assume mental disability can be determined by the public. I don’t think we can with the info available. Gut feelings will just reinforce your biases.
Obesity itself is probably too vague and non specific to be usefully called a disease. The basic measurement for obesity, BMI, would classify bodybuilders or strengthen based athletes as obese. Bodybuilders and strong people can often be unhealthy, but it’s not quite the same as someone with high body fat.
Even then, people who are obese because of high body fat might have their lives shortened through multiple mechanisms. It could be heart disease that kills them, skeletal problems due to weight, immune issues, digestive issues, practically every organ can be affected. Any or all of these things could occur in a chronically obese person, so even if pathologized, obesity is less useful as a diagnosis.
Excess weight is bad, but you can calculate weight/height without a doctor. Focusing on better nutrition, eating habits, and exercise is the solution, even if you’re young and have a high metabolism. That sugar in our food needs to be taxed or regulated, as economic incentives drive obesity rather than people being uniquely stupid or culturally degenerate.