Sugar is the world’s most socially acceptable coping mechanism. After a long day at work, people reach for hot chocolate, snap off a square of chocolate, or crack open a sugary drink—and genuinely feel better.
However, new research suggests that although the brain may feel calmer, the body may still be under stress.
A new study, published in the International Journal of Psychophysiology, explored whether sugar affects the body during relaxing activities such as massage and quiet rest.
Researchers studied 94 healthy adults, who were randomly assigned to one of four groups: glucose plus massage, glucose plus rest, water plus massage, or water plus rest—followed by a sustained attention task.
The glucose drink contained 75 grams of glucose dissolved in water—roughly equivalent to the sugar in about two cans of regular soda, or about 20 teaspoons of sugar. Researchers measured blood glucose, blood pressure, heart activity, and signals from both the body’s alert and relaxation systems throughout the experiment. Blood glucose levels were assessed before the drink, before the massage or rest session, and again before the attention task.
The results showed that both massage and rest still worked as expected: Participants felt less aroused, and their bodies showed clear signs of relaxation. However, among those who consumed glucose, part of the body’s alert system didn’t fully wind down, suggesting that sugar may keep the body from fully settling into a relaxed state.
“Sugar borrows a moment of calm from the dopamine system and charges the interest to your metabolic health,” Grant Antoine, a naturopathic doctor and precision nutrition clinical lead at Viome, told The Epoch Times. Although the brain registers comfort, the body may still be running a stress response underneath.
The Calm You Feel Isn’t the Calm You Think
The sense of comfort from sugar appears to be primarily driven by the brain’s reward system—not a whole-body relaxation response.
“The calm people feel from sugar is a neurochemical event in the reward system,” Antoine, who wasn’t part of the study, said.
The sense of calm, he said, doesn’t extend to the cardiovascular and nervous systems or to stress hormones, which remain active underneath.
“This is why a sugary snack can quietly undo the work of breathing exercises or meditation,” he said, noting that although the brain registers comfort in the moment, “the body never stops running its stress program.”
Glucose raised stress activity and made it harder for the body to relax—even during a calming intervention such as massage, Kara Seidman, a nutritionist and director of partnerships at Resbiotic Nutrition, told The Epoch Times.
“This suggests a disconnect between perceived calm and actual physiological stress,” she said.
Sugar Sends Your Body a Stress Signal
The body responds to what’s in your bloodstream.
“A sugar spike itself is a stressor,” Antoine said.
Rising blood sugar activates the body’s “fight or flight” response, increasing heart rate and blood pressure.
“Typically, we only see these changes during periods of increased stress, like exercise, but human glucose studies have shown this to occur even at rest,” he said.
What follows the spike is often worse. When blood sugar crashes below baseline, the body treats it as an emergency, releasing cortisol and adrenaline, both of which are stress hormones, to compensate.
“A single dose of sugar can actually trigger two rounds of stress activation: one on the spike up and one on the crash down,” Antoine said.
Importantly, there is no single cut-off for how much sugar causes a blood sugar spike. The effect is highly dependent on both the dose and the context. Factors such as what else was eaten, a person’s insulin sensitivity, activity level, and whether stress is already present can all influence the body’s response.
For context, the study used a glucose dose equivalent to the amount used in an oral glucose tolerance test—a large, rapidly absorbed sugar load designed to sharply raise blood sugar levels.
Studies show that consuming sugar before a stressful event can amplify the body’s hormonal response. In one study, people who consumed glucose before a social stress test—such as giving a speech or doing mental math out loud—had a larger spike in cortisol compared with those who did not.
Those with already dysregulated stress systems, such as people experiencing chronic stress, poor sleep, or burnout, may be hit hardest: Their cortisol levels tend to rise higher and stay elevated longer.
At a biological level, high blood sugar signals that energy is available—and that conditions favor action, not rest. The brain responds by shifting the body into a more alert, ready state.
Why We Crave Sugar Under Stress
Several biological and psychological forces nudge us toward sugar when we’re stressed. Cortisol boosts appetite and drives cravings for calorie-dense foods.
Stress increases levels of ghrelin, the hunger hormone, which amplifies the urge to eat. Chronic stress can make the brain “partially deaf” to leptin, the hormone that signals fullness, Antoine said.
“So you’re hungrier than normal and less able to recognize when you’ve had enough,” he said.
Sugar also genuinely works—it does provide relief, at least temporarily. Studies show that it can dampen the stress response by suppressing activity in the hypothalamic-pituitary-adrenal axis, part of the stress system that helps keep us alert and energized during prolonged stress.
However, this effect is short-lived. The relief lasts only briefly before the cycle resets and demands another dose, Antoine said.
Sugar is also rarely consumed in isolation. It’s often paired with calming activities—such as sitting down, watching something, or spending time with others—which deepens the sense of relief.
Because sugar blunts stress—even briefly—you are more likely to reach for it again the next time you feel overwhelmed. That craving, Antoine said, comes back stronger each time.
The Long-Term Cost
Over time, the cycle takes a toll.
When sugar is used repeatedly for stress relief, both insulin and cortisol can rise at the same time, creating a push-pull effect. One hormone is trying to store energy, while the other is trying to keep it circulating.
Cells may become less responsive to insulin, and persistently elevated blood sugar can contribute to inflammation, raising the risk of conditions such as Type 2 diabetes and heart disease.
Sugary drinks, fast food such as burgers and fries, pizza, and desserts typically contain empty calories and unhealthy fats, Dr. Deepak Bhatt, an interventional cardiologist and director of Mount Sinai Fuster Heart Hospital, told The Epoch Times. When stress eating becomes habitual, it can also lead to weight gain, another key risk factor for diabetes and heart disease.
None of this means that you have to cut out sugar completely—or feel guilty for reaching for it. The comfort sugar provides is real, but it’s partial. Understanding how sugar affects both the brain and the body may help people make more informed choices, especially during times of stress.
Feeling better is not just about momentary comfort—it’s also about allowing the body to fully return to a state of rest.