Well there’s a lot of reasons, actually. The main one is that not all fat people are unhealthy! There was a recent study actually (I’ll have to locate the source later, right now I’m on my iPad) that showed how a group of 200lb adults that exercised daily were actually deemed healthier than and a sedentary group of thin adults. Body mass really doesn’t say much about your health, for the most part.
Yes, obesity can raise the risk of certain illnesses, but to say that all fat people are ill is ludicrous. It’s like saying all smokers have lung cancer. That sounds absurd, doesn’t it? Well, smokers have a higher chance of lung cancer, but that doesn’t mean they do have it.
And even if being obese brings the risk of illness, it can be avoided through proper eating and thirty minutes of exercise per day. There are plenty of people I know who physically can’t lose weight even though they eat healthy and work out consistently. I myself have a near impossible time losing weight. Two summers ago I worked out five days a week for three hours each day, and ate decently healthy. I started the summer at 200lb and ended the summer at 198lb, with just a bit of muscle mass gained and maybe like… One inch lost around the waist. You really couldn’t tell a difference from start to finish other than my calves being slightly more toned.
Basically, it’s rude and demeaning to write off fat as being equivalent to unhealthy, as it isn’t true in the slightest.
All that being said, say there is someone who is fat, eats a very unhealthy diet, and never works out. You still have no right as a bystander to comment on their lifestyle. That is between them and their doctor, and the choices they make are frankly none of your business.
In summary, fat doesn’t equal unhealthy, it’s possible to be obese and healthy, and even if someone is obese and unhealthy, it’s not your business so don’t comment on it or try to make it your business.
Stay body positive and smash fatphobia! OuO