We live in a world where sugar is highly addictive and not only that but it tends to be the cheapest food to buy. Most kids in the last 20 years were never taught how to cook from scratch in school. It's generally more expensive to cook from scratch these days if you don't know what you're doing. People can easily get fat now through simply not knowing what's supposed to be good for them. "Low fat" foods may be loaded with sugar instead and make people fatter than if they'd gone for the standard full fat version. They may not know better. They'll simply follow what the packaging tells them.
"Oh, it's low fat so if I eat this, it'll help make me less fat."
If you want to lose weight, you need a high fat and low carb diet. That means less sugar. A "low fat" soft cheese will have more sugar than a full fat cheese.
Fat people are often fat through no fault of their own. A few may be due to genetic conditions (though these will number a very small amount). Those fat people may also be already in the process of losing weight snd you will never know just looking at them. So the next time you see a fat person, please think about that before you bark out some nasty judgement at them.
Nothing would hurt a fat person in the process of losing weight more than a nasty comment. Leave them alone. Either they're fat and they've yet to decide it's best to get healthy, or they're fat and they're on their way to being healthy. Either way, leave them the fuck alone unless you're a close friend who genuinely gives a fuck about their wellbeing.
I speak as a person who is in chubbyland myself. Not obese, but I can definitely stand to lose a few pounds. I know exactly what it takes, personally, to shed my excess weight. We're all unique after all. Whether you're 20lb overweight or 200lb overweight... everyone needs their own support and help in this regard. I'm lucky to be happy with myself as I am, but fat people...? The last thing they need is some sad asshole shitting on them for their weight. They are aware already.
So unless it is your personal quest to help overweight people feel better in their bid to lose wieght, just leave it alone and do something else with your time.