That is not correct advice... sorry.
Some people have no hunger. I don't because of stomach problems. People with GP do not get hunger, whether diabetic or not, because their stomachs do not empty properly.. people with slow or paralysed colons can feel the same and nauseous etc because nothing has moved. Vagus nerve damage can be absolutely horrible. Some people never feel hungry with these conditions.
People that have anorexia etc get past the point of hunger etc..
My 1st hubby with 26" waist had effectively killed off his hunger and his innards had shrunk to not being able to eat very much and never had hunger.
Please, please do not tell people not to eat unless they are hungry. For me... if I took that advice, I would never eat again!!!