Halving Sugar Intake Increases Sweet Taste Intensity in Thai Adults with Moderate to High Sugar Consumption: A Randomized Controlled Trial

Abstract

Objectives: To determine whether a 50% reduction in daily sugar intake increases sweet taste intensity among Thai adults, and whether changes in taste perception and dietary sugar intake persist after the restriction period ends.
Materials and Methods: A randomized, double-blind, controlled trial was conducted over 12 weeks among 52 healthy Thai adults. Participants were assigned to either a sugar-reduction group instructed to halve their daily sugar intake (n = 25) or a control group that maintained their usual diet (n = 27). Sweet taste intensity was evaluated using the general labeled magnitude scale at baseline, week 16 (end of restriction), and week 24 (after resumption of regular diet). The primary outcome was the proportion of participants with increased sweet taste intensity at week 16, while secondary outcomes included sweet taste intensity at week 24 and changes in dietary sugar intake.
Results: At week 16, significantly more participants in the intervention group reported heightened sweet taste intensity compared with the control group (64% vs 33.3%, p = 0.027). After participants resumed their usual diets at week 24, this difference was no longer statistically significant (44% vs 38.5%, p = 0.688). Dietary sugar intake significantly decreased during the intervention period, but partially rebounded after restriction was lifted. No significant between-group differences were observed in total energy intake or anthropometric outcomes.
Conclusion: A 12-week 50% sugar-reduction intervention increased sweet taste intensity. However, both taste perception and dietary behaviors partially reverted after the restriction was lifted, suggesting that sensory adaptation alone may not sustain long-term change.