@GetOffYourHighHorse the definition of disease isn't 'something that happens completely by chance and not influenced by any actions on the part of the person who has the disease'. Having said that, obesity itself isn't a disease. You can be obese and healthy - it's just a number, and for some people - for example, people who have lots of muscle and are very active, you can have a BMI in the obese range and have no health issues at all. What obesity is, is a risk factor for disease.
In any case, you (and lots of other people in this dumpster fire of a thread) seem to think that fat and obese people can "just lose weight if they just eat less". That's technically true, if you eat far enough below your basal metabolic rate, you will lose weight. But 'how far below' is completely different for everyone- the human body isn't a car engine and its metabolism is affected by hundreds of factors. One hugely important factor is that when you've been fat long enough, that weight becomes 'normal' for your body, and your hormones will basically do everything possible to maintain that weight - making it impossible to lose anything if you eat more than a very small number of calories, making you obsess over food, leading to all kinds of disordered eating. Why do you think that, according to most studies, anywhere from 80 to 95% of people who lose weight gain it back within 5 years? Are 80 to 95% of people weak, disgusting failures? Or could it maybe be that something else is going on?
You can't go back in time and stop people from getting fat. You can only really teach children how to take care of their bodies, and treat people who already are fat with respect instead of as morally corrupt drains on society - EVEN IF THEY CAN'T LOSE WEIGHT. Or, I mean, you can treat them like shit, and refuse to understand the complexity of fatness and obesity, but that makes you the one who is morally corrupt.
I don't claim to have the answers but I do, at least, understand the problem, which would be a good start for all of you, as well.