That underlying system responds to how you live. And lifestyle, like a car, runs on four wheels: if one has a puncture, it doesn’t matter how good the other three are - the car gets stuck.
Dr. Roshani works four wheels - Nutrition, Sleep, Stress Management, Exercise - one at a time, in that order. Nutrition comes first, because getting it right makes the next three easier - and by the time Exercise comes around, a well-fed, well-rested body tends to ask for it. Nobody changes everything at once.
What keeps it moving is self-care, not fear or guilt.