Can Stress Scramble the Signals Between Your Gut and Brain?

Feeling full seems as though it should be one of the body’s clearest messages. Food enters the stomach, the stomach fills, and the brain tells us when to stop. Yet some days fullness seems to arrive late—or becomes tangled with the desire to keep eating.

Stress may be one reason why. We often explain stress eating through cortisol, cravings, or a weakened ability to resist the siren call of comfort food. But a recent study suggests stress may sometimes act one step earlier, changing how clearly some people perceive signals coming from inside the body.

The effect was not universal. Instead, fullness may be less like a fixed gauge and more like a conversation among the gut, the brain, and the circumstances surrounding a meal. Stress may make that conversation harder to hear.

Scientists call the process of sensing and interpreting these internal messages interoception. It is how the nervous system tracks what is happening inside the body—from a racing heart to an empty or stretching stomach.

“Feeling satiation and fullness isn't a fixed fact. It's more about the perception and interpretation of signals your body sends,” says Miriam Kipping, a psychologist at Ulm University in Germany. Appetite or craving, by contrast, includes more motivational and emotional components. You can be physically full, she notes, and still want a cookie.

To investigate whether acute stress changes that perception, Kipping and colleagues asked 94 fasting adults to eat yogurt from a bowl that secretly refilled itself. The setup, called the Magic Table, used a hidden pump to keep the portion looking unchanged, leaving participants to rely more heavily on sensations from their stomachs. Each person completed the experiment after both a stressful mental-arithmetic task and a less demanding control task.

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Overall, acute stress did not blunt fullness perception for everyone. But under stress, people who reported greater difficulty regulating emotions, as well as more restrained or uncontrolled eating, consumed more yogurt before feeling full. The difference emerged at complete fullness, not at the first hint of satiation. Curiously, self-reported emotional eating did not predict the effect.

The researchers interpret that pattern as reduced sensitivity to stronger fullness signals under stress. Still, the finding is preliminary, Kipping emphasizes. But it could suggest that stress may alter gastric interoception and that it may shift with a person’s emotional state and eating patterns rather than operating as a fixed internal gauge.

Fullness does not begin or end in the stomach. As food arrives, the stomach expands, activating stretch-sensitive endings of the vagus nerve that detect this and relay information to the brainstem. As food moves into the intestine, nutrients and calories generate additional signals. The brain combines these messages with taste, memory, expectation, and reward to decide when a meal feels like enough.

“The vagus nerve connects basically every organ in your body to your brain and back,” says Guillaume de Lartigue, a neuroscientist at the Monell Chemical Senses Center and the University of Pennsylvania. “It’s this two-way communication between the body and the brain.”

Much of this unfolds outside conscious awareness. The brainstem processes incoming signals automatically, while the insula helps bring bodily sensations into awareness. Motivation, reward, and decision-making shape what we do with them.

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Where stress enters this system is less clear.  Acute stress—the racing heart and churning stomach before a big presentation, for instance—mobilizes the body for action and, for some people, suppresses eating altogether. Chronic stress involves a more prolonged strain: weeks of poor sleep while dealing with an unresolved problem at work or home, with no clear moment when the body gets to stand down.

Even within the same person, that response can change. Physiologist Rajita Sinha, the director of the Yale University Stress Center, says the effects of stress “can vary in the same person at different times in their life and different phases.” Someone who once forgot to eat when stressed might, years later, find themselves standing in front of the freezer looking for a pint of ice cream, or the other way around.

Animal studies suggest these systems may overlap. In a 2025 mouse study, de Lartigue and his colleagues activated vagal neurons that detect internal stretch. The mice ate and drank less, while brain activity associated with vigilance and stress increased. The experiment did not recreate everyday stress or measure fullness, but it revealed how closely those circuits may be connected.

De Lartigue’s lab is now investigating whether repeated stress can dampen the sensitivity of the vagal pathways that carry information from the digestive system. If those pathways become less responsive to stomach stretch or nutrient signals, the brain may receive a quieter message that a meal has been eaten.

But the evidence is not tidy: In another mouse study, chronic stress made gastric vagal fibers more sensitive, not less. Different stressors may turn different signals up or down. “What’s happening centrally” in the brain under chronic stress is also crucial and remains an active area of research, de Lartigue says.

Sinha describes stress as a “wild card” in the usual balance of energy intake and expenditure. Cortisol is often cast as the villain, but during acute stress, it helps free up energy so the body can respond. Ideally, the system settles once the threat has passed.

Problems arise when stress becomes chronic, and those adaptive systems stay activated. Habit and reward systems can then make fast-energy foods especially compelling, sometimes before we consciously register what we are doing.

That complexity matters for familiar advice to tune into your body. “I would like to reframe that and say notice what your body is doing and what your mind—what your senses—are telling you,” Sinha says. Hunger may be only one signal in the mix; exhaustion, emotion, and stress matter too.

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Kipping takes a similarly nuanced view. In her clinical work, she says, people who have lost touch with hunger and fullness sometimes begin with structure—regular meals, for example—then gradually practice noticing how the stomach feels before, during, and after eating.

The goal, then, may not be to trust every bodily message unquestioningly. It is to understand that those messages are real, dynamic, and shaped by context. “Listen to your body” sounds simple. Biology suggests listening can be a skill—and under stress, the signal itself may become harder to hear.