Consuming diet soda during pregnancy can increase a child's risk of obesity, according to a study from the National Institutes of Health.
"Our findings suggest that artificially-sweetened beverages during pregnancy are not likely to be any better at reducing the risk for later childhood obesity than sugar-sweetened beverages," said Chilin Zhang, an epidemiologist at NIH's National Institute of Child Health and Human Development.
Zhang, who was one of the several authors on the study, explained that the results showed children from mothers who consumed artificially-sweetened beverages during their pregnancy were just as likely to have higher birth weights and experience obesity by age 7 as children from mothers who consumed sugar-sweetened beverages.
She added that this risk was significantly higher than in children who were born to mothers who never consumed either of the types of beverages.
"One of the reasons we pursued this question was because artificially-sweetened beverages were widely consumed and thought of as a healthy alternative to sugar-sweetened beverages," Zhang said.
Sugar-sweetened beverages are the most common type of soda and contain natural sugar.
Artificially-sweetened beverages, commonly known as diet soda, contain numerous artificial sweeteners that mimic the sweetened taste while maintaining a reduced calorie level.
Results also indicated little difference in the birth weight between the two types of beverages.
The study sampled 918 pairs of women and children from the Danish National Birth Cohort, which studies nutrition during pregnancy in Denmark.
Data was collected from 1996-2002 through questionnaires and included follow-up studies to track the weight of the children.
Zhang explained that Denmark was one of the very few countries that had the necessary data available to conduct the study.
"In order to test our hypothesis, it really required both data from maternal diet and also information on the children's health, especially in the long term," she said.
Zhang also added that her sample was limited to mostly Caucasian women.
Maintaining a healthy diet during pregnancy is essential in ensuring the health of the mother and her child.
"Someone who has a poor diet puts themselves at higher risk of blood pressure issues or diabetes in pregnancy," said James Benson, an obstetrician at Georgetown University's MedStar Hospital.
He added that diet effects largely depend on the individual mother experiencing the pregnancy.
Benson, who was not involved in the study, described the biological process of a pregnancy as an "evolutionary conflict." He explained that while a fetus attempts to take in all of the nutrients the mother consumes, the mother's body tries to budget the nutrients for other biological functions.
As a practitioner, Benson tells his patients to maintain a well-balanced diet and increase daily food intake by 300 calories during the pregnancy but added it largely depends on weight.
"In my practice, I have about one patient not gaining enough weight for every 10 patients that's gaining too much weight," he said. "What we do is watch the weight gain and make recommendations based on that."
During pregnancy, the mother typically experiences cravings for more food and calories, which Benson said can trigger gestational diabetes.
Gestational diabetes, which Zhang noted all of the women in the study had, occurs when the mother's body fails to produce enough insulin during the pregnancy, which results in a higher blood sugar. Benson noted this was temporary and usually resolves naturally in the postpartum period.
Zhang explained that additional studies were needed to reinforce her conclusions and understand longer-term effects.
"How can we explain our findings and what are the underlying mechanisms? I think we need more research as well," she added.