What Causes Obesity

What causes obesity?
It's NOT calories in, calories out!
Eating less and exercising more is a set up for failure. Hunger will win.
What causes bodyfat to accumulate? Insulin!
If you eat glucose, this stimulates insulin, you store fat. Insulin is an anabolic hormone. Of course there are other variables like muscle mass.
If you eat low glucose which keeps insulin low, you begin to burn fat.
If you don't eat, of course your glucose is low and insulin is low, but can you maintain this and fight off hunger?