Diet soda vs water: Study reveals which beverage is better for weight loss

A two-year randomized trial involving overweight or obese adults found that diet drinks containing sugar substitutes were as effective as water for supporting weight loss. Participants in both groups lost weight, inches around their waists and hips, and reduced body fat without significant differences between the diet drink and water groups. Researchers noted that the study participants were also part of a structured weight-management program, suggesting diet beverages likely aided weight loss through substitution rather than by having a direct metabolic effect.

• A two-year randomized trial found diet drinks with non-nutritive sweeteners (NNS) were as effective as water for weight loss in overweight/obese adults.
• Participants in both the diet drink and water groups lost an average of 10.6 pounds and 8.2 pounds respectively, and maintained weight loss over two years.
• Both groups showed reductions in waist/hip measurements and body fat, with no significant differences between the groups.
• Experts suggest diet drinks contribute to weight loss by replacing higher-calorie sugar-sweetened beverages, rather than through inherent metabolic properties.
• The study was conducted at one location in England with limitations in generalizability, and a significant number of participants did not complete the full 104-week assessment.