Plenty of overweight people lie to themselves regarding their health. "I workout so despite being obese I am fine" "I eat plenty of fruit and veg so while the rest of my diet sucks I'm ok" "But I don't drink or smoke so that balances it out" Usually takes something like having a kid or some other big reality check for people to face the reality of their situation. Fact is being overweight has so many negative health effects it's mind boggling. Pretty much name any major disease which kills people and you'll see being overweight as a risk factor. Like Alzheimer's learned recently being overweight during middle age increases your chances of Alzheimer's. Heart attacks, stroke, etc you'd expect but dementia isn't something you'd think would be a serious health risk from obesity.