Objective:

To compare the effects of nonnutritive sweetened (NNS) beverages and water on body weight reduction over 104 weeks in adults participating in a behavioral weight-management program.

Approach:

• Study Design: A parallel-group, open-label SWITCH trial involving 493 adults aged 18 to 65 years with a BMI of 27 to 35, randomly assigned to consume either water or NNS beverages.
• Intervention: Participants consumed at least 2 servings of 330 mL per day of either water or NNS beverages, with a 12-week active weight-loss phase followed by a 40-week maintenance phase and a voluntary 52-week extension.
• Measurements: Change in body weight, waist and hip circumference, body composition, glycemic measures, lipids, liver biomarkers, hunger, and sugar and sweetener consumption were assessed.

Key Findings:

• Body weight decreased by 3.7 kg in the water group and 4.8 kg in the NNS beverage group, with no statistically significant between-group difference.
• Weight loss was most rapid during the initial 12-week phase, with both groups maintaining significant weight loss through week 104.
• Waist and hip circumference decreased in both groups without significant differences.
• Metabolic outcomes showed some differences, with the water group having greater reductions in glycated hemoglobin and diastolic blood pressure, while total cholesterol increased in the NNS group.

Interpretation:

Beverage assignment was not significantly associated with body weight at week 104, and both groups showed similar patterns of weight loss and metabolic changes.

Limitations:

• Only 220 out of 493 participants completed the study, potentially affecting the results.
• The study was conducted at a single site in England, limiting generalizability.
• Race and ethnicity data were not collected.

Conclusion:

Both groups maintained significant weight loss up to week 104.

Sources:

• British Journal of Nutrition