Diet drinks containing sugar substitutes proved just as effective as water for supporting weight loss in overweight or obese adults during a two-year randomized trial published in the British Journal of Nutrition, Fox News reported.
Two-Year University of Liverpool Trial Traces Weight Loss Results
The study, led by the University of Liverpool in England, tracked 493 participants ranging in age from 18 to 65 years old. Every participant had a body mass index between 27 and 35. Researchers divided the group in half, giving 22.3 ounces of water daily to one side and the same volume of soda with non-nutritive sweeteners to the other side for 104 weeks.
Participants assigned to the non-nutritive sweetener group selected from diet sodas, low-calorie fruit drinks, and flavored waters flavored primarily with aspartame, acesulfame potassium, and sucralose. At the end of the two-year period, individuals drinking diet beverages lost an average of about 10.6 pounds. Participants drinking water lost an average of about 8.2 pounds.
Waist and Hip Measurements Show Similar Reductions
Both groups maintained a meaningful weight loss across the full 104 weeks, even through the final year when regular weight-management support had ended, according to study authors. Participants in both the water and diet beverage cohorts reduced inches around their waists and hips while lowering overall body fat, though the researchers found no statistically meaningful difference between the two hydration choices.
Total cholesterol levels stayed within the healthy range for participants in both groups throughout the duration of the trial. Alix Turoff, a registered dietitian in New York City who was not involved in the research, noted to Fox News Digital that the trial compared diet beverages directly to water rather than to sugar-sweetened drinks, testing specifically whether sugar substitutes hindered weight loss efforts.
Dietitian Explains Calorie Savings Drive Trial Results
Turoff emphasized that the study does not demonstrate that diet beverages possess a direct metabolic effect causing weight loss. Instead, she explained that everyone in the trial participated in a structured weight-management program that incorporated nutrition counseling, behavioral support, and physical activity recommendations.
If someone normally drinks 250 calories of regular soda and switches to zero-calorie soda, then they’re saving calories,
Turoff told Fox News Digital. She added that the trial recorded no significant between-group differences in hunger or sugar intake at the conclusion of the research, easing common concerns that artificial sweeteners might increase appetite or trigger compensatory eating.
Study Limitations Include High Dropout Rates and Funding Source
The research faced several acknowledged limitations, including that investigators conducted the trial at a single location in England and did not collect race or ethnicity data, which restricts the broader generalizability of the findings. Out of the 493 participants who began the treatment, only 220 completed the full 104-week assessment. The second-year extension was entirely voluntary, meaning participants who stayed enrolled may have displayed higher motivation to stick with the program.
The American Beverage Association funded the trial, but study authors stated that the association did not participate in the research design, data analysis, or interpretation of the results.
Frequently Asked Questions About the Sweetener Study
- How many participants completed the full University of Liverpool trial?
- Only 220 of the initial 493 participants finished the 104-week assessment.
- Which specific artificial sweeteners were included in the test drinks?
- The primary sweeteners used across the diet sodas, flavored waters, and low-calorie fruit drinks were aspartame, acesulfame potassium, and sucralose.
- Who funded the two-year randomized trial published in the British Journal of Nutrition?
- The American Beverage Association provided funding for the study, though the authors stated the association had no role in study design, data analysis, or interpretation.
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