Artificial sweeteners might seem like a low- or no-calorie way to enjoy sweet food and not gain weight. But a new study links them to the opposite. In the report, published in the Canadian Medical Association Journal, researchers analyzed 37 studies on artificial sweeteners to see if they were successful for weight management. The studies followed more than 400,000 people for about 10 years. Seven of the studies were randomized controlled trials, a type considered to be the gold standard in scientific research.
Artificial sweeteners did not appear to help people lose weight. Instead, observational studies that looked at consumption over time suggested that people who regularly consumed them—by drinking one or more artificially-sweetened beverages a day—had a higher risk for health issues like weight gain, obesity, diabetes and heart disease.
“I think there’s an assumption that when there are zero calories, there is zero harm,” says study author Meghan Azad, an assistant professor in the department of pediatrics and child health at the University of Manitoba in Canada. “This research has made me appreciate that there’s more to it than calories alone.”
The new study adds to a growing body of research that suggests sugar substitutes are no magic bullet. “Unfortunately, the quality of evidence that would support using sweeteners is not really strong,” says Susan Swithers, a professor in the department of psychological studies at Purdue University who has also studied artificial sweeteners (but was not involved in the new study). “I think we are at a place where we can say that they don’t help.”