Just to put the cancer Research uk data into,perspective...4 in 10 cancers are preventable and the leading cause of cancer in this group is smoking and then, second is obesity.
That means that 6 in 10 cancers aren't classed as preventable. So people giving messages that obesity will lead to cancer are not telling the whole story.
I've been fat and I've been dangerously underweight. I'm now at a healthy weight and one that works for me and my build. I pay little attention to BMI because I tend to spend most of my day working with incredibly fit people who, according to BMI, are in the morbidly obese category and so I see what bollocks it really is.
Yes, being thin and eating a shit diet, smoking and drink isn't healthy....but society doesn't see that because society (and MN) already fat shame (and thin shame if we're being honest).
People are overweight for a variety of reasons, same as some people are naturally slim. Overweight people are also not a homogeneous mass of poor, stupid and uneducated like some people assume on here. My mother was overweight and she was a gynaecologist. My father is overweight and he is a GP. Neither of them uneducated. Neither of them stuffing sugar and pies and yes, their portion sizes were perfectly ok too.
When you are fat everyone judges you for what you eat, for what you wear, when you exercise (shock, horror fat people exercise too!) and just for existing. Shaming people because of how they look is disgusting. Treating people as stupid because of how they look is disgusting. What sort of society are we becoming when people get judged for not meeting the narrow criteria of what is supposed to look good? And it is looks that people are judging. Unless you have x ray vision and can see inside someone's body or have access to their medical records when how do you know their health status?
One final point. Derailing a bit. We can afford a decent NHS and decent public services. It is just a matter of priority. We just happen to have a govt that doesn't prioritise it.