a blonde losing weight

An overweight blonde went to her doctor because she wanted to loose some weight. So the doctor said eat what you usally eat for three days then skip a day then come back in a months time and u will have lost weight
so in a months time the blonde returns to her doctor 30 pounds lighter
the doctor asked her" so how do you feel?"
the blonde said "my arms and legs hurt lots and my musles ach"
the doctor said "are they sore from dieting?"
the blonde said" no from skipping"