WannaBe Ahhhh shucks, I've been morbidly obese since the age of 5 because no one told me how to eat healthily... bingo! Obesity = solved. Thanks for that. I was put on slim fast shakes at 7 years old (god bless the 90's) and have been on a low fat diet ever since. I was 19st 1lb on new years day 
Incidentally, I only started losing weight when I accepted that actually, high carb low fat diets we're advised to eat in this country dont actually work, but if you follow the Swedish dietary advice (High fat, low carb, moderate protien) you end up reversing insulin resistance (pre-diabetes), dropping weight and improving your health generally.
Here's 23 clinical studies that support that point and I can recommend a number of peer reviewed books that discuss the outcomes in depth. authoritynutrition.com/23-studies-on-low-carb-and-low-fat-diets/
The "fat people are fat because they're greedy and morally bankrupt and probably eat kittens for a snack" shit is the bit that needs to stop. Until we recognise that the "my plate" WOE is bollocks we'll always have an obesity crisis. Some people do really well on high carb, low fat diets but 65% of them regain the weight within 3 years. That number rises to 94% ten years post-loss.
If caloric in take and lethargy is purely to blame for obesity, explain why those people who lose their weight have the odds so stacked against them for weight regain? What is it about their lifestyle changes that makes it so invariably impossible to maintain?
Incidentally, those who lose weight on a low carb, high fat diet (study conducted in Sweden) have just a 34% chance of weight regain after loss, 10 year figures are due out in 2022.
Of course people are overweight because they eat the wrong things or in the wrong quantities. The question and point you're completely missing is WHY do they do that. Until we recognise that the mechanical causes of obesity are a symptom and not the primary cause of the problem there will always be an obesity crisis.