Non-nutritive sweetened beverages versus water after a 52-week weight management programme: a randomised controlled trial

Int J Obes (Lond). 2024 Jan;48(1):83-93. doi: 10.1038/s41366-023-01393-3. Epub 2023 Oct 5.


Background/objective: Sugar-sweetened beverages are a substantial source of dietary sugar that can contribute to weight gain and the risk of type 2 diabetes. Dietary guidelines recommend non-nutritive sweetened (NNS) beverages to reduce sugar consumption, however, there is a need for long-term randomised controlled trials on their use. We aimed to compare the effects of NNS beverages and water on body weight during weight loss and maintenance in a behavioural weight management programme.

Methods: In this parallel-group, open-label, controlled equivalence trial, adults with a BMI of 27-35 kg/m2 who regularly consumed cold beverages were randomised 1:1 to water or NNS beverages. Participants underwent a group behavioural weight management programme comprising weekly (during the 12-week weight-loss phase) then monthly (during the 40-week weight-maintenance phase) meetings. The primary endpoint was weight change at week 52 (equivalence: two-sided P > 0.05). Secondary endpoints included changes in anthropometrics, cardiometabolic risk factors, appetite and activity levels.

Results: Of 493 participants randomised (water: n = 246; NNS beverages: n = 247), 24.1% were NNS-naïve. At week 52, water and NNS beverages were non-equivalent, with significantly greater weight loss in the NNS beverages group. Participants consuming water maintained a weight loss of 6.1 kg over 52 weeks versus 7.5 kg with NNS beverages (difference [90% CI]: 1.4 kg [-2.6, -0.2]; p < 0.05).

Conclusions: During a 52-week behavioural weight management programme, water and NNS beverages were non-equivalent, with weight loss maintained to a statistically greater extent with NNS beverages compared with water. However, this difference was not clinically significant.

Clinical trial registration: This trial is registered with NCT02591134.

Publication types

  • Randomized Controlled Trial

MeSH terms

  • Adult
  • Beverages
  • Diabetes Mellitus, Type 2*
  • Humans
  • Non-Nutritive Sweeteners* / adverse effects
  • Randomized Controlled Trials as Topic
  • Sugar-Sweetened Beverages*
  • Water
  • Weight Loss
  • Weight Reduction Programs*


  • Non-Nutritive Sweeteners
  • Water

Associated data