Diet soda may help you cut calories in the short term, but some evidence suggests that it could cause you to crave more sweet, high-calorie food over time.
Women and people with obesity might be especially sensitive to cravings linked to artificial sweeteners, according to a study published September 28 in the journal Nutrition, Obesity, and Exercise.
Researchers brought 72 adult participants into a lab to test how their brains responded to images of high-calorie food, as shown on an MRI scan of brain areas associated with cravings.
While looking at the images, participants drank one of three beverages: water, a sugary drink, or a drink sweetened with sucralose, a zero-calorie artificial sweetener.
Then, researchers measures participants' hormones (including those linked to hunger) and observed how much they ate at a meal following the image test.
They found that for female participants and participants with obesity, drinking a diet beverage seemed to boost cravings. Areas of the brain linked to reward-seeking behavior lit up more in response to the different food imagery, compared to when they drank the sugary beverage.
However, participants didn't end up eating more after drinking the artificial sugar, and in some cases ate less. Accounting for the extra calories in the sugar-sweetened beverage, the diet beverage group actually consumed fewer calories, on average.
These findings suggest that while artificial sugar may influence how our brains crave, and respond to, the rewards of food, it's not clear from this study how artificial sweeteners affect eating behavior.
Research is mixed on whether artificial sugar helps or hinders health
Brain activity isn't necessarily an accurate predictor of how people will eat. The most recent study is helpful for directing further research, but not for drawing conclusions about artificial sweeteners just yet, according to Ted Kyle, a healthcare professional and advocacy advisor for the Obesity Society.
"This is interesting research, but it tells us nothing about the real-world effects of sweeteners on real people in real life," Kyle wrote in a commentary on the study.
The health effects of artificial sweeteners continue to be controversial, even as Americans are consuming more of them. Some research warns of health consequences such as cravings, disrupted gut health, and potentially heightened long-term risk of dementia and stroke.
Other evidence suggests low or no calorie sweeteners don't cause people to eat more, making them a tool in curbing obesity, diabetes, and other metabolic illness.
Zero-calorie sweeteners can also vary widely based on the type, ranging from sucralose and aspartame to sugar alcohols or stevia, all of which have different health concerns.
As a result, there's no one-size-fits-all verdict on diet drinks.
