Could Diet Soda during Pregnancy Mean an Overweight Child Later?

CLEVELAND – Many women who are pregnant worry about what is safe and what’s not safe to drink while expecting.

A recent study said that women with gestational diabetes who drink diet soda during their pregnancy could be putting their children at risk for weight gain.

Salena Zanotti, M.D., of Cleveland Clinic did not take part in the study, but said previous studies have shown that drinking diet soda in moderation during pregnancy is generally safe, but this most recent study is the first to look at the potential impact long-term.

Researchers looked at data from more than 900 pregnant women with gestational diabetes between 1996 and 2002.

About nine percent of the women surveyed drank at least one diet soda per day.

“Looking at those women and their children, did they have a higher risk of obesity? And what they found, when they looked up to seven years – which is a long time so far for these studies – that their infants, especially the boys, had a higher risk of being overweight and being obese,” said Dr. Zanotti. 

Researchers said the women who consumed diet soda were 60 percent more likely to have babies with a high birth weight compared with women who did not drink any diet soda during pregnancy.

Likewise, the children born to the women who drank water instead of sweetened beverages were 17 percent less likely to be overweight by age seven.

Dr. Zanotti said what remains to be determined is whether the diet soda alone was the problem, or whether the women who drank diet soda also ate diets high in fat and sugar.

She said sometimes pregnant women will eat sugary and high fat foods and think that it’s okay if they’re drinking diet soda, when really it’s only okay to drink it if they’re eating a well-balanced, low fat, higher protein diet.

“If you wanted to have an occasional soda, you could have one a day, if that’s what you want to have,” said Dr. Zanotti. “For some people they’ve given up a lot of things that they really like and this is their one vice and I think that’s fine, if they’re doing everything else correctly.” 

Dr. Zanotti said water should be a woman’s beverage of choice during pregnancy.

She said too much sugar is a problem whether it’s real sugar or a sweet substitute. Excessive sugar intake leads to excessive pregnancy weight gain, which means a higher risk of having bigger baby and a higher risk of having to deliver the baby via a cesarean section.

Complete results of the study can be found in the International Journal of Epidemiology.