Understanding how hunger and long-term dietary habits shape craving for sweet taste is key to tackling overconsumption of sugar. A new study published in Food Quality and Safety on May 20, 2026, reveals that hunger amplifies the immediate liking and physiological arousal triggered by sweetness itself, not specifically by the calories it provides. The research also shows that people who regularly consume non-nutritive sweeteners exhibit heightened activity in a brain region linked to self-control when tasting sweet solutions.
Excessive sugar intake is a major driver of obesity, type 2 diabetes, and cardiovascular disease. In response, non-nutritive sweeteners have become widely used as low-calorie alternatives. However, concerns have grown that chronic non-nutritive sweetener consumption might decouple sweet taste from metabolic energy signaling, potentially reshaping taste preferences and reward pathways in unexpected ways. Long-term trials have so far produced conflicting results, with some studies showing shifts in sweet preference and others finding no change.
Researchers from Jiangnan University in China and the University of Oxford in the United Kingdom published their findings (DOI:10.1093/fqsafe/fyag046) in the journal Food Quality and Safety. The study directly compared habitual sugar consumers and habitual non-nutritive sweetener consumers, measuring their responses to sweetness-matched solutions under both hungry and satiated conditions. Using a combination of subjective ratings, emotional assessments, electrocardiogram, and functional near-infrared spectroscopy (fNIRS), the team uncovered a dissociation between what people say they like and how their brains and bodies respond.
Participants consistently rated all sweet solutions as more enjoyable when hungry, regardless of whether those solutions contained sugar or only non-nutritive sweeteners. This hunger-driven boost in liking was accompanied by clear physiological signs of sympathetic nervous system arousal, including significantly shortened R-R intervals and increased heart rate. Contrary to the team's initial hypothesis, hunger did not selectively favor caloric sugar over non-caloric sweetness. In other words, the craving for energy made sweetness itself more appealing, not the calories behind it.
More strikingly, habitual non-nutritive sweetener consumers showed a distinct neural signature. While their self-reported liking and emotional responses did not differ from sugar consumers, fNIRS revealed significantly stronger oxygenated hemoglobin responses in their left dorsolateral prefrontal cortex (DLPFC) — a key region for cognitive control, dietary self-regulation, and resisting temptation. This neural difference emerged even though all samples were tasted blindly and matched perfectly for sweetness intensity, ruling out simple perceptual explanations.
"Hunger seems to turn up the volume on sweetness itself, making it more appealing whether it comes with calories or not," the authors said. "That was a surprise — we expected hungry people to reach specifically for sugar. But we also saw that habitual non-nutritive sweetener users showed a stronger brain response in a region linked to self-control. It is as if their brains are working a little harder to keep their sweet intake in check."
These findings offer practical guidance for public health and the food industry. Because hunger enhances the appeal of any sweet taste, replacing sugar with non-nutritive sweeteners in snacks consumed between meals might still satisfy cravings without adding calories. The heightened brain activity in habitual non-nutritive sweetener users raises the possibility that these sweeteners could help reinforce cognitive control over food choices, though this remains to be tested. For now, the study suggests that sweetness itself — not just its energy content — powerfully drives hunger-related eating behavior. Reformulating products to be less sweet overall, while ensuring they are still pleasurable, may be a more effective long-term strategy than simply swapping sugar for zero-calorie alternatives.
