|This is not a math equation. It's a word problem.|
For instance, I lose best when I do 80% fat. Not everyone is going to like that, or do well on it; I average 1850 calories a day when I eat that way.
But when you consider I used to eat low fat, averaged 1200 calories a day, and couldn't lose weight for weeks on end, we see that our bodies are chemical factories; not spreadsheets.
Eating fat encourages our bodies to burn fat; that is where the food energy is coming from, so our body shifts its chemical factories to burn fat as fuel.
If we eat large amounts of carbohydrates, our body sets up the chemical factories to burn carbs; only, unless we are marathon runners, we cannot burn up that many. The body then cannot burn fat because all their "factories" are set up for carbs.
If we cannot burn up all those carbs; we're stuck with them. The body has to get those sugars out of the blood, using insulin.
So the body turns them into... FAT.
That's how we got fat in the first place. It was never from eating fat.