People get hungry from differerent stimulii. Some of us look at pictures of food and respond to the visual stimulii by emitting digestive tract fluids in response. This makes us feel hungry, or comfortable when we are not hungry. We like to eat, we use prepared food that we purchase from the grocery store, or we buy the foodstuff to prepare the meals we consume at the retail outlet. Some of us enjoy stocking up on canned goods for the comfort it brings, while others of us actually like to read the labels on the grocery items. Having a full pantry brings me relief, as I know that groceries are in the household for a few weeks more. Ever get take-out food, bring it home, and then want something to go with it that you did not buy at the store? Most of us have experienced the need for more groceries even when we purchase take-out food from an eaterie. Some of us buy our pre-prepared food from the grocery store, and get the add-on items during the same trip. Others of us shop once or twice per month, and purchase in bulk.
Sometimes the chemical additives in food have strange effects on those individuals that consume these products. Some people will say that at least it is not genetically modified food, however, if you want to avoid "Frankenfood", you should avoid all artificial ingredients in your food.