Maybe switching from regular soda to diet doesn’t help as much as we thought.

A new study from the Medical College of Wisconsin and Marquette University links artificial sweeteners to obesity and diabetes, claiming sweeteners change how the body processes fat and uses energy.

Researchers fed groups of rats diets high in sugar or artificial sweeteners including aspartame and acesulfame potassium. After three weeks, blood samples showed significant differences in concentrations of biochemicals, fats and amino acids.

“We observed that in moderation, your body has the machinery to handle sugar,” said Brian Hoffmann, lead researcher on the study and assistant professor of biomedical engineering at the Medical College of Wisconsin and Marquette University. “It is when the system is overloaded over a long period of time that this machinery breaks down. We also observed that replacing these sugars with non-caloric artificial sweeteners leads to negative changes in fat and energy metabolism.”

Findings were presented on Sunday during the 2018 Experimental Biology meeting held in San Diego.

Before you scramble to dump out all those artificial sweeteners, researchers note this study doesn’t clearly say whether they are better or worse than sugar.

“As with other dietary components, I like to tell people moderation is the key if one finds it hard to completely cut something out of their diet,” Hoffmann said in a statement.

This is not the first research suggesting artificial sweeteners might have a negative impact on your health. Last year, a study claimed¬†drinks with artificial sweeteners could increase a person’s risk of dementia or stroke.

Four years ago, a separate study published in Nature said sweeteners have an equally direct impact on causing diabetes as sugar.