A new study reveals how sucralose tricks your brain and disrupts hunger signals—especially in people with obesity.
Sugar is one of the most common food items—and also one of the most controversial. Excess sugar consumption is linked to numerous health problems, from dental issues to diabetes. Artificial sweeteners, often used to reduce traditional sugar intake, may be healthier but are not without their controversies.
A recent study found that some artificial sweeteners may affect the brain’s appetite signals. Researchers observed that sucralose was less satisfying than sucrose, the standard table sugar.
Sucralose is an artificial sweetener, a disaccharide made of two simple sugars. It’s up to 600 times sweeter than sucrose but is not absorbed by the body in the same way. As a result, it has zero caloric value.
This may explain the observed effect: our body detects a sweet taste and prepares for incoming calories—but none arrive. The body reacts to this absence of energy.
The study involved 75 participants who acted as both the experimental and control groups over several sessions. They consumed three drinks in random order: one sweetened with sucralose, one with sucrose (regular sugar), and one plain water. Researchers used fMRI scans, blood samples, and hunger questionnaires to analyze responses.
They found that sucralose increased hunger and activity in the hypothalamus—especially among participants with obesity. It also altered how the hypothalamus communicated with other brain regions. The findings were published in Nature Metabolism.
The key could lie in hormones like insulin and GLP-1, which help regulate hunger and signal satiety to the brain. “The body uses these hormones to tell the brain you’ve consumed calories, to reduce hunger,” explains study co-author Kathleen Alanna Page. “Sucralose didn’t trigger that effect, and the hormonal response difference was more pronounced in obese participants.”
The researchers acknowledge that more studies are needed—especially long-term ones analyzing weight and eating behavior. One area of interest is how factors like gender influence the brain’s response. Notably, women in the study showed greater variability in brain activity than men, which opens the door to more focused investigation.
