The Zone Diet Concept: (read about it specifically)

This is a hypothesis diet, not well documented. It is potentially too impactful of a concept to leave out when there are no contraindications for including it. (example: Ketogenic diet trial for seizure disorders)

It completely makes sense and is included in the protocol for the DAY diet.

It is about balancing hormones through balancing carb/fat/protein ratios.

Basic concept is every time you put something in your mouth you have an approximate balance of all three. Simpler yet: just have some specific carbs, fat & protein with each intake. Nuts tend to be the perfect on the go snack as a result.

It is just habit or lack of habit that makes this happen.

The DAY diet presented here encompasses this principal.