You can fix the majority of the obese issues by removing refined carbohydrates from the diet.
Naturally occurring carbohydrates are fine.
Overconsumption of refined carbs in combination with a lack of vigorous exercise leads directly to weight gain. Each gram of carbohydrate that you store (rather than burn off) makes you also store 2.5 grams of water = 3.5 grams of "fat" on the body. Watching prime time tv with deserts, chips and crackers and ice-cream and then crashing for the night from the insulin spike and crash is behavior that needs to change.
Meat is fine, eating fats is necessary, naturally occurring carbohydrates are fine because whole food comes packed with micronutrients, fiber, vitamins, minerals etc etc as they were meant to be.
The person who posted about wine and tacos and muffins.
A muffin and coffee in the morning are fine. That's not overconsumption. A taco is perfectly fine. Tortillas are super healthy, but a couple of tacos for dinner is within reason.
Wine in moderation (two glasses per night) is probably fine and is much lower in refined carbs than beer.
Add in exercise and you are good. Not super-elite, high-end amazingly healthy, but you won't get obese from that.
Eating, for example, a bowl of cold cereal with a banana and 1 or 2% milk every day is like having a big bowl of sugar as far as your body is concerned, high glycemic meal with an insulin spike, followed by a crash — once oe twice a week would be okay. Better to have two eggs on toast or the banana with peanut butter....or intermittent fast or eggs and bacon or yogurt with a bit of fruit.
So refined sugar must go.
Sedentary people's perception of what exercise is, needs to change. Gardening for a couple hours on Saturday is nothing. Slowly riding around on a bicycle for 30 - 40 minutes is nothing. Strolling is nothing.
Need to get the heart rate up, and keep it up and have some real effort.
The old three square meals per day idea was meant for the person who works on the farm for 12-16 hours per day and therefore needs fuel. That's real work. Look at old pictures of farmers: skinny but healthy.
Overconsumption of anything is toxic, but refined carbohydrates is the worst and terrible is hydrogenated fats (margarine).
Flour
Sugar
Cookies
Pasta
Bread
Bagels
Wraps
Doughnuts
Candy
Candy bars
Soda
Crackers
Some chips
High volume of popcorn
Slurpees
High energy drinks
etc.