Change in liking following reduction in sweetness level of carbonated beverages: a randomized controlled parallel trial.

Despite recommendations to reduce sweet-tasting foods and beverage consumption, there is limited understanding of our ability to adapt to a less sweet diet and the optimal method for doing so. Thus, we conducted two parallel, double-blind, randomized controlled trials in the USA and Mexico to investigate whether different methods of reducing sweetness could change sweetness preferences. Over 6 months, habitual consumers of full-sugar sweetened (FSS-CSD) or low-calorie sweetened carbonated soft drinks (LCS-CSD) consumed a full sweetness CSD (Control), CSD with gradually decreasing sweetness levels (StepR), and a reduced sweetness test CSD (DirR). The StepR and DirR methods were similarly effective in helping the USA FSS-CSD cohort maintain their preference for reduced-sweetness CSD, without affecting sweetness intensity perception. However, neither method significantly impacted the sweetness intensity perception or preference of the USA LCS-CSD cohort, and the FSS-CSD and LCS-CSD cohorts in Mexico. Nevertheless, participants from both sweetness reduction groups in all cohorts were more willing to purchase reduced sweetness CSD compared to Control, underscoring the potential for consumer acceptance of less sweet beverages regardless of adaptation strategies.This trial was registered at www.clinicaltrials.gov as NCT04609657 and NCT05010408.