Is Diet Soda Bad For You?

Tips and Advice From the Doctors, Dietitians, Exercise Physiologists, and Psychologists at the Pritikin Longevity Center

“Is diet soda bad for you?”

You’re probably thinking of a recent study that got a lot of press (surprisingly so, since it was a very small study, and it was done on rats). The study found that 8 rats consuming saccharin-sweetened yogurt ate more food overall and put on more weight during a two-week period than 9 rats consuming sugar-sweetened yogurt.

What does this study mean as far as humans are concerned? “Nothing,” asserts Dr. Jay Kenney, Nutrition Research Specialist at the Pritikin Longevity Center. “The study was too small to be sure the results were anything more than a statistical quirk. And even if the results can be repeated, the implication for humans is what?”

What numerous studies on humans over the past several decades have found is the following:

  1. Saccharin or other artificial sweeteners have little or no impact on weight.
  2. Beverages full of sugar, like regular sodas, have a major impact. “Sugar-sweetened beverages increase overall calorie intake in both rats and humans and promote obesity,” sums up Dr. Kenney.
  3. Adding sugar to yogurt and other foods increases the calorie density (but saccharin does not), “and we know that increased calorie density is the single most important dietary factor predicting increased ad libitum [eat till you’re satisfied] calorie intake in rats and people,” adds Dr. Kenney. Put simply, the more calorie-dense foods we eat, the more calories we take in, and the fatter we get.

Bottom Line

“If you’re drinking diet beverages within the Pritikin guidelines (no more than 1 diet soft drink per day) and/or using Splenda within our suggested guidelines (no more than 6 packets per day), it is unlikely that you’re impacting your weight-loss efforts,” counsels Kimberly Gomer, Director of Nutrition at Pritikin.

It is conceivable that artificial sweeteners may undermine your attempts to adopt the Pritikin Program in that their high intensity of sweetness might mask the milder, lighter sweetness of foods like fruit, therefore making it harder for your taste buds to recognize and appreciate fruits’ flavors. But there are no credible data that artificial sweeteners alone promote increased calorie intake.

They may in fact improve your adherence to Pritikin living if using them helps you make better food choices. Some people, for example, have no problem choosing oatmeal and strawberries over a less healthy breakfast as long as the oatmeal and strawberries are sweetened with a little Splenda. Certainly, oatmeal and strawberries with Splenda are far better than, say, bagels and low-fat cream cheese.

Health Resort

Take life to the next level, and be all that you can be. That's what a vacation at Pritikin is all about. Live better. Look better. Best of all, feel better.

All-Inclusive Program

Since 1975, 100,000+ people have come to Pritikin. We are the longest-running, most scientifically documented health resort in America.

Rooms and Suites

Our newly renovated guest rooms at the health resort are spacious, serene, and amenity-rich. Each has a gorgeous garden view.


Book a Stay

A stay with us will change your life!
book now

Success Story

I'm back to my high school weight!
read story

For Questions & Reservations Call

Get more information via email

  • This field is for validation purposes and should be left unchanged.

Pritikin Newsletter

Every week we send out our email newsletter with recent articles, new recipes, special promotions, and upcoming events. Sign up today!