Quality of Food
Hunger pangs can occur even when the body does not need calories. This is because insulin, the hormone that controls blood sugar, interacts with ghrelin. Falling insulin levels cause the levels of ghrelin, and thus appetite, to increase.
Massive levels of sugar and simple carbohydrates are found in junk food. Eating it causes the amount of insulin to increase, followed by a rapid decrease. Ghrelin then rises, even though the food was eaten just an hour or so ago.
Eating even large quantities of low quality food in this way will increase appetite and activate the body’s pang response.