Drinking diet beverages as part of a diet program might help you lose more weight than drinking water, a controversial new study reports. The new research, published Tuesday in the respected journal Obesity, has been criticized over its backing from the beverage industry. But the main finding — that diet drinks don’t sabotage weight-loss efforts — isn’t that surprising.
Researchers from the University of Colorado and Temple University's Center for Obesity Research and Education reported that people who consumed three or more diet drinks a week — not only soda but pre-mixed beverages with artificial sweeteners — as part of a structured weight-loss plan lost more weight over a three-month period compared to a group of dieters who drank only water.
People at two different sites, a total of 303 men and women, ages 21-65, participated in a 12-week randomized trial, meaning they were assigned to different groups to compare different treatments. The participants had a body mass index (BMI) ranging between 27 – 40 (considered overweight or obese).
The study compared self-reported water intake with self-reported water and diet drink intake. Both groups were free to consume foods containing low-calorie sweeteners.
The most unexpected observation was that the group consuming diet drinks lost nearly 30 percent more weight compared to the water-only group. The participants in the diet drink group reported a small decrease in weekly hunger.
About 20 percent of Americans consume diet drinks on any given day, according to a report from the Centers for Disease Control and Prevention. Numerous studies have linked sugar-sweetened beverages to obesity, but cutting down on added sugars in a diet can be tough. For many people, being able to consume an artificially sweetened drink occasionally could mean the difference between sustained weight loss and failure.
While prior studies have linked artificial sweeteners with weight loss, others suggest diet soda puts you at greater risk of weight gain. A January study from Johns Hopkins University found overweight and obese people who drink diet beverages tend to eat more than people who drink sugary beverages.
Population-based studies have used databases to make possible associations between self-reported food intake and self-reported diet drink intake and body weight, finding that diet drinks can interfere with weight-loss efforts. But an association does not mean cause and effect.
While the study was funded by the American Beverage Association, this should not bias the results. When any organization (including the National Institutes of Health) funds an academic study, the monies are given to the University, not the researchers conducting the study. The research is conducted completely independently and the report represents the view of the scientists, not the sponsor. The data and report are peer-reviewed prior to publication in a scientific journal.
Certainly, the new study is not definitive and has its limitations, such as its short duration of 12 weeks. Perhaps a follow-up study will look at diet beverage consumption and long-term weight loss and maintenance.
Also, water is the gold-standard for calorie-free hydration, and the best choice for “caloric dilution” (watering down higher calorie liquids). Simply adding diet drinks to a meal plan does not insure weight loss. Neither should you add a diet drink thinking you’ll offset the calories from a high-calorie meal.
When it comes to diet drinks, as with all foods and beverages, it’s about moderation.