Why We Experience Hunger... Even When We Don't Need Food

If you were to track your thoughts throughout the day, "I'm hungry" would likely appear multiple times (perhaps alongside, "Why am I even tracking my thoughts?"). Once you notice how often food crosses your mind, you might begin to question if you're genuinely hungry every day.

But what’s behind this constant hunger?

Just to clarify: We're not discussing real starvation, nor the global and social issue of hunger. This is about hunger in generally healthy individuals with easy access to food — the kind of hunger driven by our body’s need for nutrients. Hormones and the nervous system control hunger and eating patterns. But how exactly do we recognize the desire to eat, even when we don't actually need food?

Richard Stevenson is a psychology professor at Macquarie University in Sydney, Australia, where he researches human eating behavior. He explains that hunger isn’t a sensation that everyone can identify universally. "Unlike fullness, which is unmistakable, hunger is highly variable," he notes in an email. "It’s not a consistent feeling across individuals, and some people have even claimed that stress can be mistaken for hunger."

Even certain biological signs often linked to hunger — like a growling stomach — aren't always reliable indicators. "Many people don't experience stomach sensations when asked to describe what hunger feels like," Stevenson adds. In fact, studies reveal that people often report headaches, weakness, salivation, and other sensations unrelated to the stomach as signals of hunger. Stevenson’s own research suggests that feelings of hunger and satiety are influenced by various factors, including genetic traits and psychological conditions such as depression, anxiety, and eating disorders.

Then there’s a significant factor: Our surroundings can easily trick us into thinking we need to eat, even when we’re not truly hungry.

"Seeing, smelling, or even just thinking about food," Stevenson says, can deceive us into feeling like our stomachs are demanding nourishment. "This is why food advertisements are so effective," he explains. And it affects not only our desire for food but also the amount we consume. A 2009 study found that both children and adults tend to eat more snacks after being exposed to food ads, and a 2016 review showed that food advertisements significantly increase unhealthy eating in children. Researchers even coined the term "hedonic hunger" to describe the urge to eat driven by pleasure rather than nutritional need.

This phenomenon may also offer insight into another hunger-related mystery: How can we feel starving, only to find that the hunger fades after some time or a distraction?

Stevenson suggests that the diminishing sensation of hunger could be linked to the idea that our appetite isn’t always triggered by an actual need for calories. The fleeting hunger pangs may happen because "the trigger for the hunger sensation has disappeared," he explains, or because a typical eating signal has been missed. "Time itself can also serve as a powerful cue to eat," he says. "If you usually eat around noon and miss it, you'll feel hungry once you realize what time it is."

So, what’s the secret to determining if you’re really hungry? Is there a scientific method to help resist the temptation of that bowl of chips you don’t actually need?

"In short, no," says Stevenson. "Most of our biological systems are designed to prompt us to eat when we see food or anything that reminds us of food." This worked well for our ancient ancestors, who had to hunt for energy sources. But it might not be as beneficial when we’re faced with an abundance of snacks right after a satisfying meal.