Diet Drink Myths Busted

We've all heard rumors that diet soda actually makes you fatter. Well, that's not true, according to a study done by the University of North Carolina at Chapel Hill. Replacing caloric, sugar-sweetened beverages with diet beverages could be part of an effective weight-loss strategy. But drinking plain water appears to give more health benefits.  Researchers found that swapping out sugar-sweetened beverages for non-caloric ones resulted in average weight losses of 2 to 2.5%. The Lempert Report, a newsletter for food retailers, tells more about the study. 

Researchers had hypothesized that substituting a non-caloric beverage, whether it was water or diet beverages, would lead to significant weight loss. This study was  was one of the first randomized controlled trials to explore the issue of beverage substitution and weight loss. To prove their theory, researchers compared the replacement of caloric beverages with water or diet beverages as a method of weight loss with a control group, over a six month period in adults.

People who switched to calorie-free beverages were twice as likely to lose five percent or more of their body weight than those who were not counseled to change beverages

People who drank water  had lower fasting glucose levels and better hydration levels than the control group. But it was  slightly easier for the diet beverage group to reduce calories in the short-term, at three months – as compared to the water group. People may do better slowly weaning themselves off caffeine as they transition to water, says Dr. Brie Turner-McGrievy, one of the study’s authors and Assistant Professor in the Department of Health Promotion, Education and Behavior at the University of South Carolina. Dr. Turner-McGrievy and colleagues are exploring how sweet preference plays a  role in sticking to beverage substitution over time.

“Some people may drink caloric beverages, like soda and sweet tea, because they enjoy sweet foods or have a strong preference for sweet foods and drinks. The diet drinks, which still taste sweet, may have appealed to this group of sweet likers as an easier way to discontinue their caloric beverage intake,” says Dr. Turner-McGrievy.

A few years ago I reported on a study that found a link between overweight people and diet drinks. But it was hard to say which came first -- did the diet drinks make people overweight, or did overweight people drink diet soda in an attempt to lose weight? A lot of skinny people probably feel that they can drink whatever they want,and thus don't drink low-cal sodas.  Also, there's that "halo" effect that surrounds "diet" foods. Studies have shown that people tend to eat more when they feel they can get away with it. So instead of a sugar-sweetened Coke, they might have a Diet Coke along with a bag of chips or doughnut, with the thought that the Diet Coke is going to cancel out all those calories. 

If you are swapping beverages straight across, though, it makes sense that you could lose weight. 


Since over 20 percent of America's calories come from sugar-sweetened beverages, it makes sense to switch to water or lower calorie drinks.