The type of hunger I was referring to in relation to a thin healthy person is when they reach the point mentioned in chapter one of Fuhrman's "Eat to Live", just above the sub-heading "True Hunger" he says "Stabilization at a thin, muscular weight occurs because your body gives you strong signals to eat, signals that I call 'true hunger'. True hunger maintains your muscle reserve, not your fat". Shortly afterwards, and under the sub-heading he mentions "The ability to sense true hunger, which is a mouth-and-throat sensation, does not occur until after you are eating healthfully and have a high nutrient per calorie diet".
This is what's puzzling me. He appears to be describing the SAME type of true hunger as on a fast to completion. He says "when the period of withdrawal from excessive eating of unhealthy foods and caffeine is over, you can be in touch with true hunger", and that's his experience with thousands of patients.
Looks the same type of hunger to me as that which Shelton describes on a fast.