I believe your whole premise is wrong. I only ever eat "clean food" (haven't really tried fast food for 10-15 years) and can easily go over 4 kkcal in one sitting. Feel just fine afterwards, the stomach can stretch very far if you work at it hard enough.

Nuts, cheese, and vegetable oils are really energy dense.

I also don't consider myself to be a glutton a have a BMI of 21.