Its funny that you associate how big someone is to their appetites.
Someone can be hungry and fat at the same time. Here is an experiment. Go out today at noon. You will see fat people who are going to eat. Eating provides energy for ones bodies. Calories will be burned throughout the day for energy. Because the body uses food for its energy (like gas for a car) humans will need to constantly consume in order to survive. So people, believe it or not, will actually eat several times a day FOR YEARS.
Crazy huh? Sorry didn't mean to insult just thought you knew this already
Considering you are the one who brought up our poor people, I figured you would understand that when we talk about being "hungry" we are not talking about the day to day hunger we all feel when we need to eat, but "hunger" as a way of living over the long term, of being so poor one cannot meet thier caloric requirements over weeks and months, hunger as a state of living, not as a biological warning to eat.
It is in this comparsion, where the concept of our obese poor people being "hungry" does not make any sense, and it is this version of "hungry (i.e. starving)" that most of the rest of the worlds poor deals with in a day to day basis.