A recent two‑year randomized trial conducted by researchers at the University of Liverpool has provided new insight into the role of diet beverages in weight‑loss programs. The study enrolled 493 adults, ages 18 to 65, whose body‑mass index ranged from 27 to 35, placing them in the overweight or obese categories.
Study design and beverage assignment
Participants were split into two equal groups. One group was instructed to consume 22.3 ounces (about two cans) of plain water each day, while the other group received the same volume of non‑nutritive‑sweetener (NNS) drinks – a mix of diet sodas, low‑calorie fruit drinks, and flavored waters. The primary sweeteners used were aspartame, acesulfame potassium and sucralose. Both groups followed a structured weight‑management program that included nutrition counseling, behavioral support and physical‑activity recommendations.
Weight‑loss outcomes
After 104 weeks, the diet‑beverage group had lost an average of 10.6 pounds, whereas the water group lost about 8.2 pounds. Both cohorts also reported reductions in waist and hip measurements and a decrease in body‑fat percentage. Importantly, there were no statistically significant differences between the groups in terms of hunger levels or overall sugar intake at the study’s conclusion.
Health markers
Cholesterol levels remained within healthy ranges for participants in both arms of the trial, and no adverse health events were linked to the consumption of the diet drinks.
Expert commentary
Alix Turoff, a registered dietitian based in New York City, emphasized that the study does not prove diet beverages cause weight loss. “Everyone in the study was participating in a structured weight‑management program,” she told Fox News Digital. “The main value of including diet beverages comes down to substitution – not that these beverages have a magical metabolic effect.” She added that swapping a 250‑calorie regular soda for a zero‑calorie alternative can save calories, but she still recommends water as the primary source of hydration.
Funding and limitations
The trial was funded by the American Beverage Association, though the researchers stated the association had no role in study design, data analysis or interpretation. Limitations noted by the authors include the single‑site nature of the research (conducted in England) and the lack of race‑ and ethnicity‑specific data, which may affect the generalizability of the findings. Additionally, only 220 of the original 493 participants completed the full 104‑week assessment, suggesting that those who remained may have been more motivated.
What this means for consumers
For individuals seeking to lose weight, the study suggests that diet beverages can be a viable alternative to water when used as a calorie‑free substitute for sugary drinks. While water remains the healthiest hydration choice, the findings indicate that moderate consumption of diet drinks does not impede weight‑loss progress and may help some people stay on track without feeling deprived.
Takeaway
Overall, the research adds to a growing body of evidence that non‑nutritive‑sweetener drinks are not inherently harmful to weight‑loss efforts when paired with a comprehensive lifestyle program. Consumers can feel reassured that choosing a diet beverage over a sugary soda is unlikely to sabotage their goals, though water should still be the cornerstone of daily fluid intake.
Original reporting: Fox News (HLL/CB) — read the source article.
