Effects of non-nutritive sweeteners on body weight: a systematic review and meta-analysis of randomized controlled trial (RCT) studies.

Purposes: Controversy has emerged regarding the impact of non-nutritive sweeteners (NNS) on body weight. This systematic review and meta-analysis of randomized controlled trials aims to assess the effect of NNS intake on body weight change.

Results: Of the 3327 studies retrieved, 19 met the eligibility criteria for inclusion in the meta-analysis. Compared to the control group, the experimental group that replaced daily caloric sugars with NNS showed significant weight change (MD = -0.79 kg; 95% CI: [-1.55, -0.04]; P = 0.04; I² = 84) When grouped by study duration, the effect of NNS intervention on weight change was significant in studies lasting less than 18 weeks (MD = -0.91 kg; 95% CI: [-1.70, -0.12]; P = 0.02), but minimal in studies longer than 18 weeks (P = 0.51). According to the weight status of the participants, the effect of NNS on body weight was statistically significant only in the normal weight group (MD = -0.97 kg; 95% CI: [-1.40, -0.54]; P < 0.01) and the mixed weight group (comprising normal and overweight individuals) (MD= -1.59 kg, 95% CI: [-2.62, -0.57]; P < 0.01), not in the obese group (MD = -0.646 kg; 95% CI: [-1.839, 0.546]; P = 0.29). In the comparator group, NNS had a greater effect only when compared with caloric sugars (MD= -0.94 kg, P = 0.04). Significant weight differences were also observed in the population with diabetes (MD = -1.56 kg, P < 0.01), but not in the nondiabetic population.

Conclusion: Our study indicates that replacing sugar with NNS leads to weight loss, particularly in normal-weight participants who received the intervention for less than 18 weeks and those with diabetes. For the overweight, it is still advisable to focus on active weight intervention strategies, using NNS only as an auxiliary measure to replace the caloric sugars in the daily diet during weight intervention. This information can inform evidence-based clinical decision-making.