Researchers say expectant mothers who consume artificially sweetened beverages may double their children’s risk of being overweight at 1 year old.

Expectant mothers want the best for their children. But new evidence suggests diet sodas and other artificially sweetened beverages may not be good things.

A study released Monday in JAMA Pediatrics suggests artificial noncaloric sweeteners — those often used to replace sugar — consumed during pregnancy could give a child twice as great a chance of being overweight at 1 year old.

“To our knowledge, our results provide the first human evidence that artificial sweetener consumption during pregnancy may increase the risk of early childhood overweight,” the researchers concluded. “Given the current epidemic of childhood obesity and the widespread consumption of artificial sweeteners, further research is warranted.”

With an epidemic of obesity plaguing the United States and other developed countries, researchers across the globe are attempting to discover exactly what is propelling the growing waistlines.

In the United States, a third of adults and children are now obese, according to the U.S. Centers for Disease Control and Prevention (CDC).

While added sugar intake is strongly associated with obesity and related conditions, including type 2 diabetes, artificially sweetened beverages, including diet sodas, have become increasingly popular.

Research has shown consumption of diet sodas was associated with significantly greater risks of metabolic syndrome and type 2 diabetes. Meanwhile, beverage manufacturers say diet sodas can be an effective tool for weight loss.

The majority of the research on how artificial sweeteners can affect a developing fetus has been performed on animals.

The new research offers some insight into exactly how a mother’s beverage choice can affect her child.

Read More: Get the Facts on Childhood Obesity »

In their study, children’s health researchers associated with the University of Manitoba in Canada and other research schools used data collected from 2,413 pregnant women.

Nearly 30 percent of these women reported drinking artificially sweetened beverages and about 5 percent reported consuming them daily.

Researchers found children born to mothers who drank artificially sweetened beverages had a doubled risk of being overweight at 1 year old. These effects, researchers say, were not explained by the mother’s body mass index (BMI), quality of her diet, total energy intake, or other obesity risk factors.

Other evidence suggests that chronic artificial sweetener consumption can disrupt how the body processes glucose or how the gut bacteria help with metabolism.

Overall, the research team found soda consumption is associated with obesity, diabetes, smoking, and poor diet quality. All of these factors can increase the likelihood of obesity.

Researchers said consumption of artificially sweetened beverages was also related to a shorter period of breastfeeding and earlier introduction of solid foods, which are two other risk factors for childhood obesity.

In an accompanying editorial, Mark A. Pereira, Ph.D., of the University of Minnesota, and Dr. Matthew W. Gillman of Harvard Medical School, said the new findings were “intriguing” and warrant more research.

Read More: How Can We Fix the Epidemic of Overweight Children »

The U.S. Food and Drug Administration (FDA) has approved six artificial sweeteners for use in foods and beverages: acesulfame potassium, aspartame, saccharin, sucralose, neotame, and, most recently, advantame.

Their effects on pregnant women and unborn children continue to be explored. One study suggested the more artificially sweetened beverages an expectant mother consumed, the more likely she was to deliver her child preterm.

Other research suggests increased consumption of artificially sweetened sodas by pregnant women may contribute to the development of allergies and asthma in children.

Interestingly enough, researchers found no such correlation in sugar-sweetened beverage drinkers.

Pereira and Gillman say that because pregnant women need to drink up to three-quarters of a gallon more of fluid per day than what is normally recommended, they may be tempted to quench their thirsts with artificially sweetened beverages.

“Until more safety data are available, pregnant women should consider [safe] water for proper hydration and as the beverage of choice,” they concluded in their editorial.