Side Effects of Artificial Sweeteners May Make You Want to Eat More, Study Warns

Sucralose affects part of the brain linked to motivation and decision making skills, study warns.

New research suggests that artificial sweeteners like Splenda may stimulate areas of the brain that control hunger, potentially increasing the risk of weight gain.

According to a study published in the journal Nature Metabolism on March 26, sucralose, also sold by the brand name Splenda, affects the area of the brain linked with controlling motivation and decision making skills, but it also can increase a person’s appetite.

The findings come amid rising concerns about the negative health effects of artificial sweeteners. Research published in 2017 suggested artificial sweeteners like Equal, Stevia, and Splenda may cause a person to gain weight instead of lose it. It may also increase their risk of type 2 diabetes and high blood pressure.

A study published last year by researchers from the Cleveland Clinic linked the artificial sweetener Xylitol to an increased risk of blood clots and stroke. Another Cleveland Clinic study also linked Erythritol to increased blood clot, heart attack and stroke risks.

In 2023, the World Health Organization declared aspartame, commonly known by the brand name Equal, as a possible carcinogen based on a review of prior research. The U.S. Food and Drug Administration (FDA), disagreed with the determination and argued it was generally safe to ingest.

For this most recent study, researchers from the University of Southern California (USC) Keck School of Medicine, led by Dr. Katie Page, studied the effects of sugar compared to sucralose in 75 young adults.

Researchers took fasting blood sugar levels and conducted a Functional Magnetic Resonance Imaging (fMRI) scan. Participants then consumed one of three drinks, received another fMRI, and had blood sugar levels tested 10 minutes later, 35 minutes later and 120 minutes later. They were then asked to rate their hunger levels.

Participants drank either a glass of water containing 75 grams of sucrose, the sugar equivalent of a 16-ounce soda, or water with enough sucralose to match the sweetness, or plain unsweetened water.

According to the findings, participants who drank the water with sucralose experienced an increase in appetite by nearly 20%. Researchers said sucralose also stimulated blood flow in a part of the brain linked to motivation and decision making skills. The data indicated Sucralose seemed to interfere with appetite regulation.

Sucralose is a key ingredient in some sugar substitutes including brands like Splenda, Sukrana, SucraPlus, Zerocal and others. Sucralose is roughly 600 times sweeter than sugar and is often used in diet food and drinks to make them lower calorie and help people lose weight.

Researchers determined that when people consume artificial sweeteners, like Splenda, their brain receives a signal that triggers an increase in appetite.

The brain is designed to respond to natural sugars, but artificial sweeteners may confuse the brain, they hypothesized. Sweeteners like Splenda signal the brain without delivering the calories, which may then signal the brain to eat more.

“Sucralose, compared to sucrose and water, results in increased functional connections between the hypothalamus and brain regions involved in motivation and somatosensory processing,” the research team concluded. “These findings suggest that non-caloric sweeteners could affect key mechanisms in the hypothalamus responsible for appetite regulation.”