Diet soda. We love it or hate it. But there's no doubt that consumption is on the rise. More Americans than ever are drinking diet colas, along with other zero- and low-calorie alternatives.
While diet drink consumption is up across the entire population — about 1 in 5 of us consume them — it's higher-income, middle-aged women who are most likely to be sipping diet drinks, according to a recent Centers for Disease Control and Prevention survey.
As this increase happens, there's also evidence that Americans are drinking less sugar-sweetened soda. So the big question is, will swapping Coke for Diet Coke make any difference for people trying to manage their weight? Two recent studies suggest it just might.
Overweight adolescents who received home deliveries of water and zero-calorie drinks for one year did significantly better at limiting weight gain compared to a similar group of teens who continued drinking sugary beverages, according to a study by researchers at Boston Children's Hospital. (For more on the study, click on the audio button above to hear the radio piece.)
How much better? "We found there was a difference of just over four pounds," says Cara Ebbeling of Harvard Medical School.
It may not sound terribly impressive — four pounds in a year. But these teens were counseled to change just one thing: their drinks. It's the best evidence yet that swapping sugary drinks for zero-calorie options may influence weight significantly.
Yet there have been some concerns that diet soda might increase our appetites and prompt us to eat more. Well, a recent study suggests this is not the case, at least in the short term.
Danish researcher Bjorn Richelsen of Aarhus University Hospital compared what happened when volunteers drank Diet Coke, water, milk and sugar-sweetened Coke.
"Our conclusion was quite clear," says Richelsen. Sugary coke led people to be slightly hungrier and to eat more. But Diet Coke had a more neutral effect on appetite. Volunteers did not increase their caloric intake in the four hours after drinking Diet Coke.
"We found if you're drinking soft drinks without calories it behaves [on the appetite] exactly like drinking water," Richelsen tells me.
Now, longer-term studies are needed to see if this neutral effect holds up, but it's redeeming for those who feel diet drinks are a helpful strategy.
None of the researchers I interviewed for this story recommend we run out and buy diet drinks, however. They all agree water is best.
"We're still learning a lot about diet soda," says Robert Lustig of the University of California, San Francisco.
He's been pushing for Americans to make drastic cuts in sugar consumption. And he says since liquid calories — in the form of soda, juices and sports drinks — account for about one-third of the sugar we consume, he suggests cutting them out is a good start: They are the low-hanging fruit.
"If you got rid of 33 percent [of calories by eliminating sugary drinks,] you'd be knocking our added-sugar consumption down from from 450 calories a day to 300 calories per day [on average]," says Lustig.
Not an insignificant reduction. He says if diet soda is the baby step to wean people from sugar, maybe that's not a bad thing.
"I liken diet soda to methadone," he says — the drug used to wean people off heroin. Not ideal, but perhaps effective.