A recent two-year randomized trial conducted by the University of Liverpool in England suggests that diet drinks containing sugar substitutes are just as effective as water for aiding weight loss in overweight or obese adults. The study included 493 participants aged between 18 and 65, all with a body mass index (BMI) ranging from 27 to 35.
Participants were divided into two groups: one group consumed 22.3 ounces of water daily, while the other group drank an equivalent amount of soda featuring non-nutritive sweeteners, roughly two cans, over the 104-week study. Those in the sweetened drinks group had a variety of options, such as diet sodas, low-calorie fruit drinks, and flavored waters, with primary sweeteners being aspartame, acesulfame potassium, and sucralose.
At the end of the two years, individuals who had diet beverages lost approximately 10.6 pounds, compared to a weight loss of about 8.2 pounds for those who drank water. Interestingly, both groups maintained a significant weight loss over the study duration, even during the final year when regular weight-management support was reduced.
Participants from both groups experienced reductions in waist and hip measurements and body fat percentages, with no significant differences observed between those consuming diet drinks and those drinking water. Moreover, total cholesterol levels remained within healthy ranges for both sets of participants.
These findings were published in the British Journal of Nutrition, prompting insights from nutrition specialists like Alix Turoff, a registered dietitian in New York City. She pointed out that the research doesn’t definitively link diet beverages to weight loss on their own, as everyone was engaged in a structured weight-management program that provided nutritional advice, behavioral aid, and exercise tips.
Turoff emphasized that the primary benefit of diet beverages lies in their potential to replace higher-calorie options rather than their inherent metabolic effects. Notably, this study specifically compared diet beverages with water rather than with sugary drinks, which serves to evaluate whether using sugar substitutes might obstruct weight loss efforts.
In her analysis, Turoff suggested that if an individual typically consumes 250 calories from regular soda and switches to zero-calorie soda, they effectively reduce their calorie intake. However, she contested that the findings do not equate diet drinks with water nutritionally.
Interestingly, the study noted no significant differences in hunger levels or sugar intake between groups at the trial’s conclusion, raising questions about concerns that artificial sweeteners could heighten appetite or lead to compensatory eating behaviors.
While she recommends water as the primary hydration option, Turoff believes individuals should not feel apprehensive about consuming diet drinks, as they’re not guaranteed to hinder fat loss or induce weight gain.
That said, there were some limitations to the study; it was carried out in one location in England and did not gather data on race or ethnicity, which could impact the broader applicability of the results. Additionally, of the initial 493 participants, only 220 completed the full 104-week assessment, and the second year was optional—indicating the possibility that those who continued might have been more motivated.
Though the American Beverage Association funded the trial, the authors clarified that it did not play a role in the study’s design, data analysis, or interpretation.
