Welcome to brain Stuff from How Stuff Works. Hey, brain Stuff, Lauren Vogel bond here. If you're anything like me and you were to keep track of some of your thoughts during a given day, Gosh, I'm hungry would appear on the list a few times, along with perhaps why am I keeping track of my thoughts? But why do we often feel hungry? Let's be clear, we're not talking about actual starvation or hunger as a pervasive global and social issue, which it is and is a whole other episode or seven.
We're talking about hunger in typically healthy people with comfortable access to food, the hunger that arises from the physiological need for nutrients to survive. Hormones and the nervous system regulate hunger and eating habits. But how the heck do we recognize when we want to eat, even when we actually don't need food. We spoke via email with Richard Stevenson, a professor of psychology at Macquarie University in Sydney, Australia, where he studies human eating behavior. He says that hunger
is by no means a universally identifiable sensation. He wrote, unlike fullness, which there is no mistaking hunger is very varied. It is not a consistent sensation across people, and it has been claimed that feeling stressed can be confused with it. Even some of the biological functions that people associate with hunger a growling stomach, for instance, aren't entirely full proof cues. Stephenson said many people do not report stomach sensations when
asked to describe what being hungry is like. Indeed, reports show that people cite headaches, weakness, mouthwatering, and other non stomach related sensations as signs of hunger. Stephenson has also done research that indicates feelings of hunger and fullness are influenced by a myriad of factors, including genetic and psychological
differences like depression, anxiety, and eating disorders. Then there's a really big fact our environment can easily convince us into thinking it's time to eat, whether we're hungry or not. Stevenson said that seeing, smelling, or even thinking about food will trick us into believing that our stomach is crying out for nutrients. He pointed out that this is why advertisements for food products work so well, and that affects not just appetite, but how much food we actually consume.
A two thousand nine studies showed that both children and adults eat more snacks after exposure to food advertising, and a review found that food adds significantly increase unhealthy food intake in children. In fact, researchers coined the term hedonic hunger to describe the drive for food consumption unrelated to the need for calories. This phenomenon might also give us
a clue to another mystery of hunger. How can we claim ourselves ravenous only to find after time passes or a distraction interrupts whatever triggered the hunger, paying that hunger has passed us by. Stevenson says this waning hunger could be related to the idea that our appetite isn't always activated by an actual need for calories, and that quote time is a potent queue to eat. If you usually eat at midday and you miss this, you will feel hungry if you notice the time. So what's the trick
to deciding whether you're truly hungry? Is there a scientific method for being able to push away that bowl of chips that you don't need? Stevenson said, in a word, no, most of our biological machinery is geared to make us eat when we see food or things that remind us of food, which was terrific for our ancient ancestors when humans had to spend a lot of time searching for energy sources, but it might leave us at a disadvantage when surrounded by a huge spread of snacks right after
a filling meal. Today's episode was written by Kate Kirshner and produced by Tyler Clang. For more on this and lots of other filling topics, visit our home planet, how stuff Works dot com. M