University of Liverpool diet drink weight loss study

The SWITCH trial, a 104-week study conducted by the University of Liverpool and the University of Leeds, investigated whether diet beverages containing non-nutritive sweeteners—such as aspartame, acesulfame-K, and sucralose—affect weight loss compared to water consumption.

Published in the British Journal of Nutrition, the research followed 493 overweight or obese adults participating in a structured weight management program. The study found that those consuming diet drinks lost an average of 4.8 kg (10.6 lbs), while the water group lost an average of 3.7 kg (8.2 lbs). Researchers concluded this difference was “statistically insignificant.”

Both groups experienced improvements in metabolic health and body composition. The study found no significant differences in hunger levels or reductions in waist and hip circumferences between the two groups, and no clinically meaningful differences in blood pressure or cholesterol. Results indicated that non-nutritive sweetened beverages are as effective as water for long-term weight management.

Lead researchers, including Professor Joanne Harrold and Professor Jason Halford, stated that the findings do not support concerns that sweeteners disrupt appetite or hinder weight control. While the study was funded by the American Beverage Association, the authors clarified that the organization had no involvement in the analysis or reporting of the results.