This Is Your Brain on Diet Soda: How Fake Sugar Makes You Overeat

Research suggests artificial sweeteners like saccharin and aspartame trick our brains into being unable to control our energy intake.

splenda-615.jpgavrene/Flickr

Critics of New York's proposed soda ban have pointed out that the measure contains some major loopholes. Convenience stores would still be free to sell large, sugary drinks, for example. Sweetened alcoholic beverages are also exempted from the bill. And researchers Mayor Bloomberg cited think the whole thing might backfire. But perhaps the biggest omission in Mayor Bloomberg's plan has to do with an entirely other class of fizzy, sweetened drink: diet sodas.

In fairness to Bloomberg, the science up until now linking diet beverages to poorer health outcomes has been inconclusive, at best. We think there might be a connection to heart attack and stroke, but many researchers challenge those findings. Another study has associated diet soda with bigger waistlines, but there again, the scientists couldn't confirm whether the relationship was causal.

The murky waters of diet soda science may have just gotten a little clearer, though. New research shows that the sugar substitutes used in diet beverages actually change how our brains' reward areas work.

Researchers took 24 young adults, half of whom were habitual diet soda drinkers who consumed a sugar-free beverage once a day or more. The other half avoided diet soda. Hooking them up to brain scanning equipment, the scientists fed each group of study participants a stream of water sweetened alternately by natural and artificial sweeteners.

Because the brain's reward center is also responsible for controlling energy intake and the motivation to eat, the scientists believe that their results help explain why diet sodas appear to drive people to consume more food than they should:

One of the strongest links seen was diminishing activation of an area known as the caudate head as a recruit's diet soda consumption climbed. This area is associated with the food motivation and reward system. Green and Murphy also point out that decreased activation of this brain region has been linked with elevated risk of obesity.

[...]

"The brain normally uses a learned relationship between sweet taste and the delivery of calories to help it regulate food intake," Swithers explains. But when a sweet food unreliably delivers bonus calories, the brain "suddenly has no idea what to expect." Confused, she says, this regulator of food intake learns to ignore sweet tastes in its predictions of a food's energy content.

It's worth remembering that this is a small-scale study, performed in a way that leaves room for error. Still, it's the latest report suggesting that a scientific connection may exist between diet sodas and poor health -- a finding that could expand the scope of anti-obesity efforts.

Via Paul Kedrosky

Presented by

Brian Fung is the technology writer at National Journal. He was previously an associate editor at The Atlantic and has written for Foreign Policy and The Washington Post.

Saving the Bees

Honeybees contribute more than $15 billion to the U.S. economy. A short documentary considers how desperate beekeepers are trying to keep their hives alive.

Join the Discussion

After you comment, click Post. If you’re not already logged in you will be asked to log in or register.

blog comments powered by Disqus

Video

How to Cook Spaghetti Squash (and Why)

Cooking for yourself is one of the surest ways to eat well.

Video

Before Tinder, a Tree

Looking for your soulmate? Write a letter to the "Bridegroom's Oak" in Germany.

Video

The Health Benefits of Going Outside

People spend too much time indoors. One solution: ecotherapy.

Video

Where High Tech Meets the 1950s

Why did Green Bank, West Virginia, ban wireless signals? For science.

Video

Yes, Quidditch Is Real

How J.K. Rowling's magical sport spread from Hogwarts to college campuses

Video

Would You Live in a Treehouse?

A treehouse can be an ideal office space, vacation rental, and way of reconnecting with your youth.

More in Health

Just In