Hunger amplifies sweet taste appeal regardless of calories, study finds

A study published in Food Quality and Safety on May 20, 2026, reveals that hunger significantly increases the appeal of sweet taste, irrespective of whether the sweetness comes from sugar or non-nutritive sweeteners (NNS). The research also indicates that individuals who habitually consume NNS exhibit heightened activity in a brain region associated with self-control when tasting sweet solutions, suggesting long-term use may strengthen cognitive regulation during eating.

Excessive sugar intake is a major contributor to obesity, type 2 diabetes, and cardiovascular disease, prompting widespread use of NNS as low-calorie alternatives. However, concerns have emerged that chronic NNS consumption might uncouple sweet taste from metabolic energy signaling, potentially reshaping taste preferences and reward pathways. Long-term trials have yielded conflicting results, with some studies showing shifts in sweet preference and others finding no change. This study aimed to investigate how metabolic state and habitual NNS use jointly influence sweet preference.

Researchers from Jiangnan University in China and the University of Oxford in the United Kingdom compared habitual sugar consumers and habitual NNS consumers, measuring their responses to sweetness-matched solutions under both hungry and satiated conditions. Using subjective ratings, emotional assessments, electrocardiogram (ECG), and functional near-infrared spectroscopy (fNIRS), the team uncovered a dissociation between self-reported liking and brain/body responses.

Participants consistently rated all sweet solutions as more enjoyable when hungry, regardless of whether they contained sugar or only NNS. This hunger-driven boost in liking was accompanied by physiological signs of sympathetic nervous system arousal, including shortened R-R intervals and increased heart rate. Contrary to the team's hypothesis, hunger did not selectively favor caloric sugar over non-caloric sweetness. The craving for energy made sweetness itself more appealing, not the calories behind it.

More strikingly, habitual NNS 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 (O₂Hb) responses in the left dorsolateral prefrontal cortex (DLPFC)—a key region for cognitive control and dietary self-regulation. This neural difference emerged even though all samples were tasted blindly and matched for sweetness intensity, ruling out simple perceptual explanations. The study's emotion analysis involved a relatively small sample of 15 participants per group, so those findings should be interpreted with caution.

"Hunger seems to turn up the volume on sweetness itself, making it more appealing whether it comes with calories or not," the authors said. "We also saw that habitual NNS 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 NNS in snacks consumed between meals might still satisfy cravings without adding calories. The heightened brain activity in habitual NNS users raises the possibility that these sweeteners could help reinforce cognitive control over food choices, though this remains to be tested. 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.

The study was funded by the National Key Research and Development Program of China (Grant No. 2025YFF1107600) and the Collaborative Innovation Center of Food Safety and Quality Control in Jiangsu Province, China. For more details, see the original publication at https://doi.org/10.1093/fqsafe/fyag046.