Sucralose Causes Brain Changes that Increase Appetite

The U.S. Food and Drug Administration (FDA) approved sucralose in 1998 for use in food as a sweetener. Six hundred times sweeter than table sugar, sucralose has found its way into over 6,000 food products, including baked goods, beverages, chewing gum, gelatins, and frozen dairy desserts. Despite requests urging the FDA to reevaluate artificial sweeteners, including sucralose, the agency insists sucralose is heat stable, has no harmful effect on the reproductive and nervous systems, does not cause cancer, and does not adversely affect metabolism. Yet, studies have found sucralose is linked to leukemia, weight gain, obesity, diabetes, liver inflammation, metabolic dysfunction, and is genotoxic and breaks down human DNA. And now, a new study in Nature Metabolism found that it can cause brain changes that increase the appetite.

The study from the University of Southern California’s Keck School of Medicine reports that sucralose increases activity in the hypothalamus, an area of the brain that regulates appetite and body weight. Study author Dr. Kathleen Page explained that, particularly in individuals suffering from obesity, sucralose caused a significant activation of that brain area, leading to greater ratings of hunger. Dr. Page, an endocrinologist and expert in hormones and diabetes, noted that studies in animal models have shown that artificial sweeteners like sucralose affect the brain, where it interprets the signal of sweetness but with no nutrients to go along with it. Dr. Page explained that it confuses the brain and makes animals hungrier. Thus, she and her colleagues wondered if the same mechanism might happen in humans. Page shared:

“If your body is expecting a calorie because of the sweetness, but doesn’t get the calorie it’s expecting, that could change the way the brain is primed to crave those substances over time.”

To test their hypothesis, scientists examined how 75 participants responded to three drinks—plain water, sucralose-sweetened water, and sugar-sweetened water—consumed on separate occasions. Participants underwent MRI brain scans, blood tests, and hunger surveys before and after each drink. Results showed that sucralose increased activity in the hypothalamus, a brain region that governs background processes in the body, like regulating hunger, temperature, and tiredness. Likewise, it increased connections to areas linked to motivation and decision-making, especially in obese individuals. According to Dr. Page, this suggests sucralose may heighten cravings and influence eating behavior. Blood tests also revealed that sugar triggered appetite-suppressing hormones, but sucralose did not, with this effect more pronounced in obese participants. The body uses these hormones to tell the brain that calories have been consumed in order to decrease hunger.

The study demonstrated that women showed more significant brain activity changes after sucralose, which they state warrants further research and indicates that individual characteristics, such as sex, adiposity, and insulin resistance, appear to affect how the hypothalamus interprets sweet taste and metabolic signals related to appetite control. The researchers also plan to investigate sucralose’s effects on children. The authors wrote that considering the prevalent consumption of non-caloric sweeteners, it is vital to conduct thorough studies to clarify their long-term health ramifications. Or eliminate them altogether. Of course, that feat may prove difficult since the FDA states it has reviewed more than 110 studies designed to identify possible toxic effects of sucralose and gives it a clean bill of health. And like the rest of the nation’s illness-provoking, profit-driven healthcare system, the Calorie Control Council (CCC)—funded by its members, which are manufacturers and suppliers of low- and reduced-calorie foods—eagerly dispels any and all damaging “myths” about sucralose.

Nonetheless, evidence exists proving it is time to take a hard pause on sucralose. Besides increasing the appetite, as presented in the study by Dr. Page and others over a decade ago, research demonstrated that sucralose consumption also raises blood sugar levels. Indeed, even though it contains no calories and is not metabolized into glucose, the fake sweetener has been shown to indirectly influence blood sugar regulation in other ways. Even though it is not broken down into glucose like sugar is, which directly affects blood sugar, sucralose’s interaction with systems in the body, especially the gut and brain, indicates it negatively impacts metabolism.

One key mechanism involves the gut microbiota. A study published in 2014 in Nature found that consumption of artificial sweeteners, including sucralose, alters the composition and function of gut bacteria, leading to glucose intolerance. Glucose intolerance reflects the body’s reduced ability to regulate blood sugar effectively, which can result in elevated glucose levels after meals. These microbial changes proved significant enough to cause metabolic issues, and the effects were transferable to germ-free mice via fecal transplantation, establishing the microbiota’s role. In healthy human subjects, parallel patterns were observed, suggesting that sucralose could disrupt blood sugar control even in non-diabetic individuals.

Both of these studies are troubling and beg the question: Why are artificial sweeteners like sucralose still on the market? According to recent data, the global sucralose market generates significant revenue, with estimates varying slightly across sources. Based on available data, the market was valued at approximately $4.09 billion in 2024 and is projected to reach $4.46 billion in 2025, reflecting an annual growth rate of about 8.9 percent. Again, as stated earlier, studies continuously indicate that sucralose consumption is linked to leukemia, weight gain, obesity, diabetes, liver inflammation, metabolic dysfunction, and other illnesses. And, significantly, the fake sweetener sucralose damages the super-important gut microbiota, which helps digest food, support immunity, regulate metabolism, protect gut health by preventing harmful bacteria from causing inflammation and disease, and affect mood and brain health.