I look at being overweight a lot differently after my experience.

Many, maybe most, people look at obese and overweight people and just figure they have no willpower or desire to be normal weight. If they would only push away from the table sooner they would not be so fat. I also thought that way as I myself got fat.

But I have since found out it is not as simple as that. I am not saying self control has nothing do do with it. Of course it does. But hormones also play a BIG role. There are controlled trials now that show two different groups eating the exact same calories but different food mix and one group will lose weight while the other does not or a lesser amount of weight loss. A calorie is not a calorie when it comes to how the body utilizes that calorie. A calorie of wood sawdust is not the same as a calorie of rib eye steak is not the same as a calorie of sugar. Because the body does not metabolize them the same nor does it have the same insulin response the same. They are not metabolized the same and the different response by insulin and glucagon tells the body if it goes to fat storage or somewhere else. Insulin is the key. A steak will have of certain calorie size will create a vastly different insulin response than the same calories of sugar. Not sure about saw dust. :-)

In isocaloric diets in studies there was found about a 300 calorie difference in metabolism between the group on a high carb (but same calories) vs a low carb diet. 300 calorie difference in metabolic rate will account for the 3-5 pound weight gain per year additional fat. Three pounds of weight gain a year for 33 years and you have the extra hundred pounds I gained (all while on insulin shots which definitely make people gain weight). I had tons of insulin in my system even before taking the insulin injections.

Once I got my insulin level under controll I lost the weight. I eat like a pig. I just no longer eat stuff that raises my insulin. My last insulin assay was in the single digits.

So self control has a lot to do with weight gain. But it is less about the calories and instead the kind of foods eaten and how the body reacts with insulin. WITH HIGH INSULIN LEVELS A BODY CAN NOT BURN BODY FAT. Period.

A few ways to lower insulin (and reverse insulin resistance).
1. Caloric restriction. Starving oneself. But it doesn't work very well. For two reasons. The body recognizes it is not getting as much nutrition and goes into conservation mode by lowering the metabolic rate. So there has to be a significant reduction of calories to offset this lower metabolism (and being tired and cold if in the winter). The other reason it doesn't work very well is hunger always wins eventually as long as food is readily available. The brain sends out hungar signals and the person is always hungry.
2. Quit eating the foods that raise insulin levels. Easy peasy. What raises insulin? Carbohydrates. Nearly all grain products and starchy vegetables. What raises insulin very little? Meat and leafy green vegetables that are low in carbohydrates. If a person wants to lose weight they HAVE to lower their insulin levels. Full stop. Some ways of doing that are easier than others.

It is not rocket science. It just does not fit the modern medical, nutritional or big food business narative. It is as much about hormone response as it is calories. Both matter. One gets a lot of attention, the other doesn't.

Fat people mostly eat too much of the wrong foods/drinks that raise their insulin levels which causes insulin resistance and weight gain. Feed someone only hamburger or ribeye steak and water with nothing else for a month and watch them lose fat. Eat all they want. Don't go hungry. Just don't eat the stuff that raises insulin.

My opinion based on my experience. I'm not a nutritionists, thank goodness. I don't know if I could live with myself in that profession and have to toe the official dietary guidelines and watch people kill themselves over my guidlines.