High on Health: Got Cravings? Your Gut May Be to Blame

Cravings: We all get them from time to time, and some of us are better than others at resisting that chocolate bar or extra slice of pie. Sometimes nothing is better than a bit of comfort food to improve our moods. But what drives the need for those salty or sweet goodies? Scientists believe the gut may have a say in what our minds are telling us we want to eat.

Does Your Gut Influence Your Cravings?

For years, scientists believed food cravings came almost entirely from psychology, hormones, habits, and the environment. Today, researchers are studying another possible influence: the trillions of microbes living in our digestive tracts.

These microbes communicate with the brain through what scientists call the gut-brain axis, a two-way communication system involving the nervous system, hormones, immune signals, and chemicals produced by gut bacteria. Researchers are investigating whether those signals may affect appetite, feelings of fullness, food choices, and even cravings, although they emphasize that they are still studying the connections.

PubMed published a review of 37 studies on how bacteria in the digestive system might influence what we eat. They found that 28 reported a link between gut microbiome and eating behavior or factors that influence it. In other words, several studies suggest that the types of bacteria living in the gut may be connected to hunger hormones, appetite, and even how much people eat.

Your Brain Likes Rewards

Foods high in sugar, salt, and fat taste great, but they also activate the brain’s reward system by releasing dopamine, a chemical linked to pleasure and motivation. The American Heart Association (AMA) explained that cravings are often triggered by the brain’s reward pathways rather than hunger.

“Different things can trigger them – smells or visual cues, for example,” Dr. Rajita Sinha, a professor of psychiatry and neuroscience at Yale University School of Medicine in New Haven, Connecticut, told the AMA. “In the case of food, our sensory systems trigger the motivational or reward pathways in the brain. You don’t need to see the food per se, but people, places and things that remind you of a food that’s rewarding will do it. That motivational signal will fire up our brains.”

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The smell of fresh cookies, the sight of a bag of chips, or even hearing someone open a soda can may trigger cravings before you’re physically hungry. These cues activate memories and reward pathways in the brain.

Sometimes a craving is simply your body’s way of telling you it needs energy. Going too long without eating can increase hunger hormones, making high-calorie foods seem especially appealing. Sweet foods provide quick energy, while salty snacks are often paired with fat, making them highly satisfying.

Cravings can also be learned. If you always eat popcorn at the movies or ice cream after a stressful day, your brain begins to associate those situations with certain foods. Stress, boredom, or celebrations can lead people to seek out comfort foods because they’ve become associated with positive feelings or emotional relief.

And then there are highly-processed foods. These unhealthy snacks are carefully formulated to satisfy what’s called the “bliss point,” which is a combination of sugar, salt, and fat that makes foods very yummy and encourages us to keep eating them.

Maybe your grandmother was right when she said to trust your gut – she probably just didn’t realize your gut came with trillions of tiny roommates, each with their own interests. Whether they’re quietly influencing your next trip to the cookie jar or simply along for the ride is something scientists are still trying to figure out. Until then, your sweet tooth can continue pleading the Fifth.